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OBJECTIVE: To explore the risk factors of early femoral head necrosis in patients with femoral neck fracture after operation, and to establish a nomogram prediction model. METHODS: A total of 167 patients with femoral neck fracture from January 2020 to April 2022 were selected and divided into necrosis group and non-necrosis group according to whether femoral head necrosis occurred in the early postoperative period. There were 21 males and 17 females in the necrosis group, aged from 33 to 72 years old, with an average of (53.49±10.96) years old, and the time from injury to operation ranged from 40 to 67 hours, with average time of(53.46±7.23) hours. There were 72 males and 57 females in the non-necrosis group, aged from 18 to 83 years, with an average of (52.78±12.55) years old, and the time from injury to operation was 18 to 65 hours, with an average time of(39.88±7.79) hours. The potential influencing factors, including patient gender, diabetes mellitus, hypertension, chronic liver disease, posterior inclination angle of the femoral head, operation mode, fracture displacement, fracture line location, preoperative braking traction, screw arrangement mode, reduction quality, age, body mass index(BMI), and injury to operation time were subjected to single factor analysis. Logistic multivariate regression analysis was conducted for factors with a significance level of P<0.05. RESULTS: The incidence of femoral head necrosis in 167 patients with femoral neck fracture was 22.76%. The following factors were identified as independent risk factors for early postoperative femoral head necrosis in patients with femoral neck fractures:coexisting diabetes[OR=5.139, 95%CI(1.405, 18.793), P=0.013], displaced fracture [OR=3.723, 95%CI(1.105, 12.541), P=0.034], preoperative immobilization[OR=3.444, 95%CI(1.038, 11.427), P=0.043], quality of reduction [OR=3.524, 95%CI(1.676, 7.411), P=0.001], and time from injury to surgery[OR=1.270, 95%CI(1.154, 1.399), P=0.000]. The Hosmer-Lemeshow goodness-of-fit test(χ2=3.951, P=0.862), the area under the receiver operator characteristic(ROC) curve was 0.944[P<0.001, 95%CI(0.903, 0.987)], with a sensitivity of 89.50%, the specificity was 88.40%, the maximum Youden index was 0.779, and the overall trend of the model correction curve was close to the ideal curve. Model regression equation was Z=1.637 × diabetes + 1.314× fracture displacement+1.237 × preoperative braking traction+1.260 × reduction quality + 0.239×injury to operation time-18.310. CONCLUSION: The occurrence of early femoral head necrosis in patients with femoral neck fracture postoperatively is affected by multiple factors. The risk early warning model established according to the factors has good predictive efficacy.

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BACKGROUND: To investigate the performance of a radiomics model based on gray-scale ultrasonography (US) for the preoperative non-invasive prediction of ipsilateral axillary lymph node (ALN) metastasis in patients with breast cancer (BC). METHODS: A total of 192 pathologically confirmed BC patients were included in this study. The training set was comprised of 132 patients from hospital 1 and the test set was comprised of 60 patients from hospital 2. All patients underwent US before percutaneous core biopsy and the results of ALN status reported by a radiologist with 12 years of experience were recorded. Radiomic features were extracted from the gray-scale US images. Max-relevance and min-redundancy (MRMR) and least absolute shrinkage and selection operator (LASSO) were used for data dimension reduction and feature selection. A radiomics model was constructed using LASSO and was validated using the leave group out cross-validation (LGOCV) method. The performance of the model was validated with receiver operating characteristic (ROC), calibration curve, and decision curve analysis. RESULTS: A total of 860 features were extracted from the gray-scale US images of each breast lesion, and 9 radiomic features were selected for model construction. The area under the curve (AUC), sensitivity, and specificity of the model for predicting ALN metastasis were 0.85, 78.9%, and 77.3% in the training set and 0.65, 68.0%, and 79.4% in the test set, respectively. The prediction performance of the model was significantly higher than that of the radiologist (AUC: 0.85 vs. 0.59, P<0.01) in the training set and was slightly higher than that of the radiologist (AUC: 0.65 vs. 0.63, P>0.05) in the test set. CONCLUSIONS: The non-invasive radiomics model has the ability to predict ALN metastasis for patients with breast cancer and may outperform US-reported ALN status performed by the radiologist.

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PURPOSE: To evaluate tissue stiffness values around breast lesions and stiff rim sign for the differentiation of benign and malignant lesions. METHODS: A total of 192 patients (mean age, 44.6 ± 13.6 years) with 199 breast lesions were included in this retrospective study. All lesions were pathologically proven by US-guided core needle biopsy (CNB), Mammotome biopsy, or surgery. We first observed the presence or absence of a stiff rim sign, which was defined as a red or orange halo around the breast lesion. The shell around the breast lesion on SWE was then automatically drawn by machine, with a width of 1 mm, 2 mm, and 3 mm. The elasticity moduli of the lesion and surrounding tissue were recorded, including maximum elasticity (Emax), mean elasticity (Emean), minimum elasticity (Emin), and elasticity ratio (shell/lesion ratio). The optimal thresholds of elasticity moduli were calculated according to the receiver operating characteristic (ROC) curve. RESULTS: There were 75 malignant lesions and 124 benign ones. The average Emax and Emean of lesions and shell were significantly higher in the malignant group than in the benign group (P < 0.05). The optimal cut-off value of Emax for diagnosing malignant lesions was 101.7 kPa, with a sensitivity of 66.3% and specificity of 87.9%. The optimal cut-off value of Emean was 29.1 kPa, with a sensitivity of 65.3% and specificity of 79.8%. The stiff rim sign had the highest diagnostic performance for malignancy as compared with other elastic parameters, with an accuracy of 88.4%. However, measuring peritumoral tissue stiffness can achieve relatively high sensitivity, whereas specificity was not improved significantly. CONCLUSIONS: The stiffness of tissue surrounding breast malignancies was significantly higher than the surrounding benign lesions. Stiff rim sign has the potential to improve the diagnostic performance of breast lesions.

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Therapeutic vaccines represent a promising immunotherapeutic modality against cancer. Discovery and validation of antigens is the key to develop effective anti-cancer vaccines. Neoantigens, arising from somatic mutations in individual cancers, are considered as ideal cancer vaccine targets because of their immunogenicity and lack of expression in normal tissues. However, only few databases support convenient access to these neoantigens for use in vaccines. To address this gap, we developed a web-accessible database, called NeoPeptide, which contains most of the important characteristics of neoantigens (such as mutation site, subunit sequence, major histocompatibility complex restriction) derived from published literature and other immunological resources. NeoPeptide also provides links to resources for further characterization of the novel features of these neoantigens. NeoPeptide will be regularly updated with newly identified and published neoantigens. Our work will help researchers in identifying neoantigens in different cancers and hasten the search for appropriate cancer vaccine candidates.

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PURPOSE: To evaluate the value and diagnostic performance of virtual touch tissue imaging quantification (VTIQ) and to determine the optimum cut-off value for differential diagnosis between benign and malignant breast lesions. METHODS: Conventional ultrasonography (US) and VTIQ were performed in 454 patients with 466 breast lesions with a Siemens Acuson S3000 ultrasound machine. All lesions were assessed by an ultrasound Breast Imaging Reporting and Data System (BI-RADS) and confirmed by histopathology. The maximum, mean, and minimum shear wave velocity (SWV) values were quantitatively measured in m/s within the regions of interest (ROIs) and ranged from 0.5 to 10 m/s. The sensitivity, specificity, accuracy, and area under the receiver operating curve (AUC) of the VTIQ, BI-RADS, and combined data were compared. RESULTS: Among the 466 breast lesions, 266 were benign and 200 were malignant. All of the SWV values of the malignant lesions were significantly greater than those of the benign ones (P < 0.05). The optimal cut-off values for SWVmax, SWVmin, SWVmean, and SWVmax/SWVmin obtained from ROC analysis were 5.37 m/s, 3.08 m/s, 4.04 m/s, and 1.83, respectively. Logistic regression analysis revealed that BI-RADS was an independent risk factor for the differential diagnosis of breast lesions, whereas SWV values were not independent risk factors. CONCLUSIONS: VTIQ is useful in the differential diagnosis between benign and malignant breast lesions. The combination of VTIQ and ultrasonic BI-RADS can improve the diagnostic performance.

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In this study, we evaluated the effect of the herbicide propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino) benzoate (ZJ0273) on barley growth and explored the potential to trigger growth recovery through the application of branched-chain amino acids (BCAAs). Barley plants were foliar-sprayed with various concentrations of ZJ0273 (100, 500, or 1000 mg/L) at the four-leaf stage. Increasing either the herbicide concentration or measurement time after herbicide treatment significantly impaired plant morphological parameters such as plant height and biomass, and affected physiological indexes, i.e. maximal photochemical efficiency (Fv/Fm), quantum yield of photosystem II (ФPSII), net photosynthetic rate (Pn), and chlorophyll meter value (soil and plant analyzer development (SPAD)). Cellular injury of herbicide-treated plants was also evidenced by increased levels of reactive oxygen species (ROS) and antioxidative enzyme activity. Elevated levels of herbicide significantly reduced the activity of acetolactate synthase (ALS)-a key enzyme in the biosynthesis of BCAAs. In a separate experiment, growth recovery in herbicide-stressed barley plants was studied using various concentrations of BCAAs (10, 50, 100, and 200 mg/L). Increasing BCAA concentration in growth media significantly increased the biomass of herbicide-stressed barley seedlings, but had no significant effect on non-stressed plants. Further, BCAAs (100 mg/L) significantly down-regulated ROS and consequently antioxidant enzyme levels in herbicide-stressed plants. Our results showed that exogenous application of BCAAs could reverse the inhibitory effects of ZJ0273 by restoring protein biosynthesis in barley seedlings.

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OBJECTIVE: To find and identify HLA-A*0201 restricted cytotoxic T lymphocyte (CTL) epitopes from epidermal growth factor pathway substrate number 8 (Eps8) for specific immunotherapy based on Eps8-derived epitopes in clinic. METHODS: Online biological softwares involved C-proteasomal cleavage, MHC class I binding affinity and TAP transport efficiency were used for prediction of HLA-A*0201 restricted epitopes from Eps8. Then, T2-binding assays and peptide/MHC complex stability tests were used to further verify the predicted epitopes. Specific secretion of IFN-γ from human CTL was assayed using the IFN-γ ELISPOT kit, and cytolytic activity was measured by a 4-h lactate dehydrogenase (LDH) release assay. Finally, the functional effects in vivo were measured in HLA-A*0201/Kb transgenic (Tg) mice. RESULTS: Four natural epitopes were designed through online biological softwares. Of the four epitopes selected, p360-368 was found to have the high binding affinity to HLA-A*0201, while p101-109 and p276-284 showed moderate affinities. DC50 of peptide/MHC complexes of the natural epitopes mentioned were all longer than 8 h. In functional assays with human PBMNC in vitro and in HLA-A*0201/Kb transgenic mice in vivo, CTLs primed by each epitope (p101-109, p276-284 and p360-368) secreted IFN-γ and were toxic to cancer cells from a variety of tissue types in an HLA-A*0201-restricted and Eps8-specific manner. CONCLUSION: Natural epitopes (p101-109, p276-284 and p360-368) may be the HLA-A*0201 restricted epitope derived from Eps8.

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Based on three manually excavated trenches (projection length of 21 m, width of 1 m) along a typical Karst hillslope, the changing trends for soil-bedrock structure, average water content of soil profile and soil-bedrock interface water content along each individual trench were studied. The effect of irregular bedrock topography on soil moisture distribution was discussed. The results showed that the surface topography was inconsistent with the bedrock topography in the Karst hill-slopes. The bedrock topography was highly irregular with a maximum variation coefficient of 82%. The distribution pattern of soil profile of moisture was significantly affected by the underlying undulant bedrock. The soil water content was related to slope position when the fluctuation was gentle, and displayed a linear increase from upslope to downslope. When the bedrock fluctuation increased, the downslope linear increasing trend for soil water content became unapparent, and the spatial continuity of soil moisture was weakened. The soil moisture was converged in rock dents and cracks. The average water content of soil profile was significantly positively correlated with the soil-bedrock interface water content, while the latter responded more sensitively to the bedrock fluctuation.

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This study was purposed to investigate the feasibility of high resolution melting (HRM) in the detection of JAK2V617F mutation in patients with myeloproliferative neoplasm (MPN). The 29 marrow samples randomly selected from patients with clinically diagnosed MPN from January 2008 to January 2011 were detected by HRM method. The results of HRM analysis were compared with that detected by allele specific polymerase chain reaction (AS-PCR) and DNA direct sequencing. The results showed that the JAK2V617F mutations were detected in 11 (37.9%, 11/29) cases by HRM, and its comparability with the direct sequencing result was 100%. While the consistency of AS-PCR with the direct sequencing was moderate (Kappa = 0.179, P = 0.316). It is concluded that the HRM analysis may be an optimal method for clinical screening of JAK2V617F mutation due to its simplicity and promptness with a high specificity.

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In order to explore the phosphorus (P) release process and its supply mechanism in tea tree rhizosphere soil, an exogenous P adsorption and culture experiment was conducted to study the P desorption process and characters in the tea tree rhizosphere soils having been cultivated for different years and derived from different parent materials. The least squares method was used to fit the isotherms of P desorption kinetics. There was an obvious difference in the P desorption process between the rhizosphere soils and non-rhizosphere soils. The P desorption ability of the rhizosphere soils was significantly higher than that of the non-rhizosphere soils. As compared with non-rhizosphere soils, rhizosphere soils had higher available P content, P desorption rate, and beta value (desorbed P of per unit adsorbed P), with the average increment being 5.49 mg x kg(-1), 1.7%, and 24.4%, respectively. The P desorption ability of the rhizosphere soils derived from different parent materials was in the order of granite > quaternary red clay > slate. The average available P content and P desorption ability of the rhizosphere soils increased with increasing cultivation years.

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OBJECTIVE: To explore the diagnostic value with BI-RADS lexicon and high-frequency color doppler ultrasonic scoring for breast diseases. METHODS: A total of 108 breast lesions were studied with BI-RADS lexicon and high-frequency color doppler ultrasonic scoring, and compared with pathologic results. Calculated the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value. RESULTS: Of these 108 lesions, 65(60.19%) were pathologically confirmed to be benign and 43(39.82%) to be malignant. There were no statistically significant differences between BI-RADS lexicon and high-frequency color doppler ultrasonic scoring in the diagnosis of breast lesions (P > 0.05). CONCLUSION: Both of BI- RADS lexicon and high-frequency color doppler ultrasonic scoring have a higher value for diagnosing breast disease in clinical application, and BI-RADS lexicon provides the normalized and standardized reporting data for clinical doctor in diagnosing breast disease, It is more conducive to guide clinicians with correct judgment and active treatment for breast disease.

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OBJECTIVE: ß-blockers (BBs) with different pharmacological properties may have heterogeneous effects on sympathetic nervous activity (SNA) and central aortic pressure (CAP), which are independent cardiovascular factors for hypertension. Hence, we analyzed the effects of bisoprolol and atenolol on SNA and CAP in hypertensive patients. METHODS: This was a prospective, randomized, controlled study in 109 never-treated hypertensive subjects randomized to bisoprolol (5 mg) or atenolol (50 mg) for 4-8 weeks. SNA, baroreflex sensitivity (BRS) and heart rate (HR) variability (HRV) were measured using power spectral analysis using a Finometer. CAP and related parameters were determined using the SphygmoCor device (pulse wave analysis). RESULTS: Both drugs were similarly effective in reducing brachial BP. However, central systolic BP (-14±10 mm Hg vs -6±9 mm Hg; P<0.001) and aortic pulse pressure (-3±10 mm Hg vs +3±8 mm Hg; P<0.001) decreased more significantly with bisoprolol than with atenolol. The augmentation index at a HR of 75 bpm (AIxatHR75) was significantly decreased (29%±11% to 25%±12%; P = 0.026) in the bisoprolol group only. Furthermore, the change in BRS in the bisoprolol group (3.99±4.19 ms/mmHg) was higher than in the atenolol group (2.66±3.78 ms/mmHg), although not statistically significant (P>0.05). BRS was stable when RHR was controlled (RHR≤65 bpm), and the two treatments had similar effects on the low frequency/high frequency (HF) ratio and on HF. CONCLUSION: BBs seem to have different effects on arterial distensibility and compliance in hypertensive subjects. Compared with atenolol, bisoprolol may have a better effect on CAP. TRIAL REGISTRATION: ClinicalTrials.gov NCT01762436.

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OBJECTIVE: To explore the diagnostic values of breast imaging and reporting data system (BI-RADS) and ultrasonic elastography (UE) for benign and malignant breast lesions. METHODS: A total of 122 breast lesions were studied with BI-RADS and UE scoring to compare the sensitivity and specificity according to the pathologic results. Receiver operating characteristic (ROC) curves were used to assess the diagnostic value of BI-RADS, UE and combination. RESULTS: Among them, pathological examinations showed that there were 72 benign and 50 malignant cases. Statistically significant differences in specificity existed between BI-RADS lexicon (as ≥ 4) and UE or combination (P < 0.05) while sensitivity showed no difference (P > 0.05); Statistically significant differences in sensitivity existed between BI-RADS (as ≥ 4B) and UE or combination (P < 0.05) while there was no difference in specificity (P > 0.05); No statistically significant differences existed between UE or combination. The area under the ROC curve was above 0.7. CONCLUSION: Both BI-RADS and UE have a great diagnostic value for breast disease. UE is somewhat superior to BI-RADS. However, the value of combination may be more significant.

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Despite recent significant advances in the treatment of hematological malignancies, relapse of this disease is of great note with the existence of the minimal residual disease (MRD). Tumour peptide vaccine seems to be one of the effective immunotherapies for eliminating tumor cells of MRD. This review focuses on the late results of clinical trails of peptide vaccination protocols targeting WT1, RHAMM, BCR-ABL, PR1 in hematological malignancies and the development of specific immune responses to PRAME and Survivin peptides. An outlook to heteroclitic peptides, new adjuvants, combined peptide vaccines and Ad-tWT1 vaccine is also given to further explore the possibility to enhance the efficacy of the peptide vaccine.

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To test the hypothesis that a mobilization of endothelial progenitor cells (EPCs) occurs after acute cerebrovascular diseases, we evaluated the number of EPCs in the process of acute stroke. A total of 203 individuals were examined, including 100 patients with ischemic strokes, 36 patients with hemorrhagic strokes and 67 healthy controls. Ninety-eight patients were observed at days 1, 7, 14 and 28 after acute stroke. Circulating EPCs were defined by the surface markers CD133/KDR and analyzed by flow cytometry. Serum high sensitivity C-reactive protein (hs-CRP) concentrations were determined by particle-enhanced immunonephelometry using the N high sensitivity CRP Reagent. Patients with acute stroke had lower numbers of EPCs (0.037+/-0.001/100 peripheral blood mononuclear cells (PMNCs) vs. 0.06+/-0.002/100 PMNCs, P<0.05) and higher levels of serum hs-CRP (1.99 vs. 0.03 mg per 100 ml, P<0.05) than control subjects after adjusting for age, sex, body mass index (BMI) and blood pressure. There were no differences in EPCs counts or serum hs-CRP levels between patients with ischemic and hemorrhagic stroke. In univariate analyses, BMI, age, systolic blood pressure (SBP), diastolic blood pressure, low-density lipoprotein (LDL), total cholesterol (T-cho), blood glucose and hs-CRP (P<0.001) were inversely correlated with EPCs counts. Multivariate analyses showed SBP and total cholesterol as independent predictors of EPCs levels. The number of EPCs gradually increased at day 7 after acute onset, remained elevated at day 14; and returned to baseline by day 28. Our results suggest a possible contribution of circulating EPCs in acute stroke. SBP and total cholesterol are independent factors of reduced EPCs numbers. A transient early increment of EPCs may result from the mobilization of EPCs in response to stroke stress.

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Near infrared (NIR) spectroscopy combined with successive projections algorithm (SPA) was investigated for the fast and nondestructive determination of total amino acids (TAA) in oilseed rape leaves. Total amino acids are important indices of the growing status of oilseed rape. A total of 150 leave samples were scanned, the calibration set was composed of 80 samples, the validation set was composed of 40 samples and the prediction set was composed of 30 samples. The optimal partial least squares (PLS) model was developed for the prediction of total amino acids in oilseed rape leaves after the performance comparison of different pretreatments, including smoothing method, standard normal variate (SNV), the first derivative and second derivative. Simultaneously, successive projections algorithm was applied for the extraction of effective wavelengths (EWs), which were thought to have least collinearity and redundancies in the spectral data. The selected effective wavelengths were used as the inputs of multiple linear regression (MLR), partial least squares (PLS) and least square-support vector machine (LS-SVM). Then the SPA-MLR, SPA-PLS and SPA-LS-SVM models were developed for performance comparison. The determination coefficient (R2) and root mean square error (RMSE) were used as the model evaluation indices. The results indicated that both SPA-MLR and SPA-PLS models were better than full-spectrum PLS model, and the best performance was achieved by SPA-LS-SVM model with R2 = 0.983 0 and RMSEP = 0.396 4. An excellent prediction precision was achieved. In conclusion, successive projections algorithm is a powerful way for effective wavelength selection, and it is feasible to determine the total amino acids in oil-seed rape leaves using near infrared spectroscopy and SPA-LS-SVM, and an excellent prediction precision was obtained. This study supplied a new and alternative approach to the further application of near infrared spectroscopy in the response of stress and on-field monitoring of the growing oilseed rape.

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The distributing and changing characteristics and content of soil heavy metals was studied using methods of field survey and sampling, indoor analysis, and pollution index were used to investigate the soil environmental quality in the tea plantations of Changsha Baili Tea Zone. The results showed that the content of soil total Pb, Hg, Cd, Cr, As, Ni basically was in the soil background value, their averages were 42.7, 0.068, 0.074, 92.2, 12.4 and 19.5 mg/kg respectively. The content of heavy metals was lower than the standard of Environmental Qualification of Nuisance Free Tea Producing Area (NY 5020-2001). Simultaneity, soil environmental quality in tea plantations of Baili Tea Zone, it answered for the second grade of State Environmental Quality Standard for Soils (GB 15618-1995), achieved safe class, and the content of soil Hg, Cd, Ni accorded to the first grade of GB 15618-1995, these results showed the Changsha Baili Tea Zone were propitious to develop nuisance free tea production. Besides the single pollution index of Cr was 0.837 and in warning class at the tea plantation of Xiangfeng, the others were all less than 0.7, and in the safe class. The integrated index of 6 tea bases was all less than 0.7, in the safe class, the soil environmental quality was cleanness on the whole at Changsha Baili Tea Zone, and the soils were suitable for non-polluted agricultural production.

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Imidacloprid has been used for many years to control planthopper Nilaparvata lugens (Stål) (Homoptera: Delphacidae) in China. To provide resistance assessment for the national insecticide resistance management program, we collected a total of 42 samples of the planthoppers from 27 locations covering eight provinces to monitor their dose responses and susceptibility changes to imidacloprid over an 11-yr period (1996-2006). Results showed that most field populations maintained susceptibility from 1996 to 2003 except for a population from Guilin, Guangxi, in 1997, which showed a low level of resistance to imidacloprid. However, surveys conducted in 2005 indicated that 16 populations from six provinces quickly developed resistance with resistance ratios ranging from 79 to 811. The data collected in 2006 revealed that the resistance levels in 12 populations collected from seven different provinces decreased slightly (RR = 107-316), except the Tongzhou population (Jiangsu Province), which developed 625-fold resistance. Dominant and intensive use of imidacloprid in a wide range of rice, Oryza savita L., growing areas might be a driving force for the resistance development. Migration of the insect also significantly boosted the resistance levels due to extensive and intensive use of imidacloprid in emigrating areas and continuous postmigration sprays of the chemical. In addition, laboratory resistance selection using imidacloprid showed that resistance ratio increased to 14-fold after 27 generations, suggesting that quick resistance development might be associated with more frequent applications of the insecticide in recent years.

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BACKGROUND: Chemical control is a major strategy for suppressing the rice stem borer, Chilo suppressalis (Walker). Owing to their high toxicity and increasing resistance development in the target insect, many insecticides will be phased out entirely in 2007 in China. Alternatives with relatively low toxicity are urgently needed to replace traditional chemicals for rice stem borer control. In this study, the authors examined four field populations of C. suppressalis for their toxicological responses to more than 20 insecticides, including a few low-toxicity organophosphates and many novel pesticides. Interpopulation resistance levels to 12 conventional insecticides were also compared. RESULTS: Based on LD(50) values, the rice stem borer was most sensitive to avermectins and fipronil (LD(50) < 1 ng larva(-1)). The stem borers exhibited the least sensitivity to endosulfan (LD(50) > 100 ng larva(-1)) and monosultap (LD(50) > 1000 ng larva(-1)). Insect growth regulators and chitin synthase inhibitors showed great efficacy against C. suppressalis, especially against populations that had developed resistance to conventional insecticides. Four field populations showed variable tolerance levels to many insecticides. LYG05 was the most susceptible population, only with a low level of resistance to monosultap (RR = 6.6). NC05 and GL05 populations exhibited intermediate tolerance levels with RR values up to 20.4 and 52.8 respectively. RA05 was the most resistant population to many insecticides, with resistance ratios up to 76.2. CONCLUSION: The results from this study provide valuable information for selection and adoption of new alternative insecticides and for resistance management of the rice stem borer.

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Based on the monitoring of soil fertility, this paper studied the characteristics of microbial biomass C (MBC) and N (MBN) in paddy soils derived from different parent materials in Hunan Province. The results showed different fertilization systems had different effects on soil MBC and MBN. After 18 years fertilization, the MBC and MBN in different paddy soils had similar variation trend, with the sequence of paddy soil derived from lake sediment > from river alluvium and quaternary red earth > from limestone > from shale. Soil MBC content ranged from 259.5 to 864.4 mg x kg(-1), while MBN ranged from 8.7 to 70.7 mg x kg(-1). Fertilization could increase soil MBC and MBN markedly. Organic fertilizer was the main element for the promotion of soil MBC and MBN, and combined application of organic and inorganic fertilizers could obtain the greatest effect. The increment of soil MBC and MBN after applying inorganic fertilizer and its combination with organic fertilizer was 407.6 and 59.2 mg x kg(-1), in maximum, and the maximum increasing rate was 102.8% and 514.8%, respectively, compared with no fertilization.

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