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In order to explore the self-priming characteristics of the self-priming pump at the mobile pump truck, this paper established a complete three-dimensional circulatory piping system including the self-priming pump, tank, valves, inlet pipe and outlet pipe. The UDF(User Defined Functions) was used to realize the acceleration-constant speed operation process of the impeller, thus reflecting the actual changing state of the rotational speed. Based on the VOF(Volume Of Fluid) multiphase flow model and the Realizable k-ε turbulence model, a coupled numerical calculation of unsteady incompressible viscous flow was conducted for its self-priming process. The results show that the self-priming process of the pump can be roughly divided into four stages: the rapid suction stage, the shock exhaust stage, the rapid exhaust period and the pump residual gas discharge stage. The proportion of each stage in the total self-priming time showed an increasing trend. During the rapid suction stage, the water level in the vertical section of the inlet pipe showed a slow and then fast-rising pattern. During the shock exhaust stage, the average gas-phase volume fraction in the volute is lower than that of the impeller, and the gas content at the volute outlet is lower than that of the impeller inlet. The region at the inlet and outer edge of the impeller consistently experience significant energy losses.

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The development of a sensitive and isothermal technique with a greatly enhanced miRNA detection signal is still technically problematic due to the low abundance of miRNA and high sequence similarities with homologous miRNAs. Herein, we propose a novel fluorescence approach for sensitive and reliable miRNA detection by integrating the palindrome sequence mediated target recycling with self-priming assisted signal reaction. In this method, a dual toehold DNA nano-probe (HT) with two functional arms is designed to mediate specific target recognition and signal amplification. In the presence of target miRNA, it binds to the recognition module of HT probe, releasing the "2" sequence to initiate strand displacement amplification (SDA) and a self-priming-induced signal reaction. Based on the elegant design, the proposed method exhibits a wide linear response range exceeding five orders of magnitude and a low limit of detection of 0.96 fM according to the 3δ rule. The non-specific signal is below 5 % for non-target miRNA detection. Taking the merits of excellent sensitivity, desirable specificity, and superior anti-interference ability, the proposed approach shows a promising prospect for detecting miRNAs in complicated biological environments and early diagnosis of diseases.

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Leakage is a high-incidence disease of embankment dams, and efficiently addressing this disease guarantees the safe operation of dams. Underwater leakage self-priming plugging technology is a new technology that utilizes the melting and solidifying characteristics of phase-change materials and the negative pressure in the leakage entry area to accurately plug the leakage. However, little is yet known about the underwater melting process of phase-change materials and how their characteristics influence the plugging effect. In this study, three kinds of phase-change materials, namely, paraffin, rosin, and stearic acid, were used to conduct underwater leakage self-priming plugging tests, observe and analyze the underwater melting process, and compare the plugging effects. The results showed that the underwater melting process of phase-change materials exhibited different plugging window periods depending on their melting points, specific heat capacities, and mobilities, which were the main factors affecting their plugging effects. In the final plugging stage, paraffin had the best plugging effect, but the material strength was low; rosin had good plugging compactness, but the fluidity performance was poor, and the material effective utilization was low; stearic acid had a low melting point but dispersed easily. Therefore, a blocking material with a suitable blocking window period can be produced by adjusting the material properties accordingly for an improved blocking effect.

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We herein present a multifunctional self-priming hairpin probe-based isothermal amplification, termed MSH, enabling one-pot detection of target nucleic acids. The sophisticatedly designed multifunctional self-priming hairpin (MSH) probe recognizes the target and rearranges to prime itself, triggering the amplification reaction powered by the continuously repeated extension, nicking, and target recycling. As a consequence, a large number of double-stranded DNA (dsDNA) amplicons are produced that could be monitored in real-time using a dsDNA-intercalating dye. Based on this unique design approach, the nucleocapsid (N) and the open reading frame 1 ab (ORF1ab) genes of SARS-CoV-2 were successfully detected down to 1.664 fM and 0.770 fM, respectively. The practical applicability of our method was validated by accurately diagnosing 60 clinical samples with 93.33% sensitivity and 96.67% specificity. This isothermal one-pot MSH technique holds great promise as a point-of-care testing protocol for the reliable detection of a wide spectrum of pathogens, particularly in resource-limited settings.

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BACKGROUND: The identification and quantification of viable Escherichia coli (E. coli) are important in multiple fields including the development of antimicrobial materials, water quality, food safety and infections diagnosis. However, the standard culture-based methods of viable E. coli detection suffer from long detection times (24 h) and complex operation, leaving the unmet requirement for fast assessing the efficiency of antimicrobial materials, early alerting the contamination of water and food, and immediately treatment of infections. RESULTS: We present a digital ß-d-glucuronidase (GUS) assay in a self-priming polydimethylsiloxane (PDMS) microfluidic chip for rapid E. coli identification and quantification. The GUS expression in viable bacteria was investigated to develop a fast GUS assay at the single-cell level. Single E. coli were stochastically discretized in picoliter chambers and identified by specific GUS activity. The digital GUS assay enabled identifying E. coli within 3 h and quantifying within 4 h for different E. coli subtypes. The specificity of our method was confirmed by using blended bacteria including E. coli, Bacillus, Shigella and Vibrio. We utilized digital GUS assay to enumerate viable E. coli after incubated with antibacterial materials for assessing the antibacterial efficiency. Moreover, the degassed chip can realize automatic sample distribution without external instruments. SIGNIFICANCE: The results demonstrated the functionality and practicability of digital GUS assay for single E. coli identification and quantification. With air-tight packaging, the developed chip has the potential for on-site E. coli analysis and could be deployed for diagnosis of E. coli infections, antimicrobial susceptibility testing, and warning the fecal pollution of water. Digital GUS assay provides a paradigm, examining the activity of metabolic enzyme, for detecting the viable bacteria other than E. coli.

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The real-time diagnostic monitoring of self-priming centrifugal pumps is essential to ensure their safe operation. Nevertheless, owing to the intricate structure and complex operational conditions inherent in such pumps, existing fault diagnosis methods encounter challenges in effectively extracting crucial fault feature information and accurately identifying fault types. Consequently, this paper introduces an intelligent fault diagnosis method tailored for self-priming centrifugal pumps. The approach amalgamates refined time-shift multiscale fluctuation dispersion entropy, cosine pairwise-constrained supervised manifold mapping, and adaptive chaotic Aquila optimization support vector machine techniques. To begin with, refined time-shift multiscale fluctuation dispersion entropy is employed to extract fault-related features, adeptly mitigating concerns related to entropy domain deviations and instability. Subsequently, the application of cosine pairwise-constrained supervised manifold mapping serves to reduce the dimensionality of the extracted fault features, thereby bolstering the efficiency and precision of the ensuing identification process. Ultimately, the utilization of an adaptive chaotic Aquila optimization support vector machine facilitates intelligent fault classification, leading to enhanced accuracy in fault identification. The experimental findings unequivocally affirm the efficacy of the proposed method in accurately discerning among various fault types in self-priming centrifugal pumps, achieving an exceptional recognition rate of 100%. Moreover, it is noteworthy that the average correct recognition rate achieved by the proposed method surpasses that of five existing intelligent fault diagnosis techniques by a significant margin, registering a notable increase of 15.97%.

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The global pandemic resulting from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its emerging variants highlights the need for convenient and accurate detection protocols to facilitate timely prevention and management of the disease. Herein, we propose a new self-priming hairpin-mediated isothermal amplification (SIAM) protocol enabling one-pot and ultrasensitive identification of SARS-CoV-2 in a multiplexed way. This approach works by targeting a specific RNA sequence with a self-priming hairpin (SP) probe and promoting continuously repeated extension and nicking reactions to produce numerous trigger molecules, which could specifically bind to molecular beacons (MBs) and produce fluorescent signals. Under an isothermal condition of 37 °C, this technique allowed for the simultaneous identification of the spike (S) and nucleocapsid (N) genes of SARS-CoV-2 down to single copy/µL levels. We further validated the practical diagnostic capabilities of the SIAM method by accurately testing 20 clinical samples with 100% sensitivity and specificity. The SIAM method has a lot of potential to be a reliable nucleic acid testing protocol to identify infections caused by a wide range of pathogens.

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The finger tapping task (FTT) is commonly used in the evaluation of dyskinesia among patients with Parkinson's disease (PD). Past research has indicated that cortical activation during FTT is different between self-priming and cue-priming conditions. To evaluate how priming conditions affect the distribution of brain activation and the reorganization of brain function, and to investigate the differences in brain activation areas during FTT between PD patients and healthy control (HC) participants, we conducted an activation likelihood estimation (ALE) meta-analysis on the existing literature. Analyses were based on data from 15 independent samples that included 181 participants with PD and 164 HC participants. We found that there was significantly more activation in the middle frontal gyrus, precentral gyrus, post-central gyrus, superior parietal lobe, inferior parietal lobule, cerebellum, and basal ganglia during FTT in PD patients than in HCs. In self-priming conditions, PD patients had less activation in the parietal lobe and insular cortex but more activation in the cerebellum than the HCs. In cue-priming conditions, the PD patients showed less activation in the cerebellum and frontal-parietal areas and more activation in the superior frontal gyrus and superior temporal gyrus than the HCs. Our study illustrates that cue-priming manipulations affect the distribution of activity in brain regions involved in motor control and motor performance in PD patients. In cue-priming conditions, brain activity in regions associated with perceptual processing and inhibitory control was enhanced, while sensory motor areas associated with attention and motor control were impaired.

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A polydimethylsiloxane (PDMS)-based self-priming microfluidic chip with cushion chambers is presented in this study for robust and easy-operation digital polymerase chain reaction (dPCR). The chip has only one inlet and can partition samples autonomously through negative pressure, provided by a de-gassed PDMS layer with a multi-level vertical branching microchannel design. Meanwhile, cushion chambers make the chip capable of very robust use for sample partitioning. Finally, the proposed microfluidic chip showed excellent performance in the absolute quantification of a target gene by performing quantitative detection of a 10-fold serial dilution DNA template. Owing to its characteristics of easy operation, low cost, and high robustness, the proposed dPCR chip is expected to further promote the extensive application of digital PCR, especially in resource-limited settings.

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We herein describe a novel technology, termed self-priming phosphorothioated hairpin-mediated isothermal amplification (SP-HAMP), enabling target nucleic acid detection. Isothermal amplification strategies are a simple process that efficiently raises the amount of nucleic acid at a constant temperature, but still has lots of problems such as the requirement of multiple exogenous primers and enzymes, which trigger non-specific background signal and increase the complexity of procedures. The key component for overcoming the above-mentioned limitations is the designed hairpin probe (HP) consisting of self-priming region along the 3' stem and the 3' overhang and phosphorothioate modifications at the 5' overhang and the specific loop part. The HP was designed to open through binding to target nucleic acid. Upon opening of HP, its self-priming (SP) region is rearranged to form a smaller hairpin whose 3' end could serve as a primer. The following extension produces the extended HP and displaces the bound target nucleic acid, which is then recycled to open another HP. Due to the reduced stability caused by the specific two phosphorothioate (PS) modifications, the 3' end of EP1 is readily rearranged to form the foldback hairpin structure, which would promote the foldback extension to produce once more extended HP. Since the two PS modifications are always located at the same positions along the 5' stem within the further extended HPs, the foldback reaction followed by the extension would be continuously repeated, consequently producing a large number of the long hairpin concatamers. Based on this unique design principle, we successfully detected even a single copy of target DNA with outstanding discrimination capability under an isothermal condition by employing only a single HP without the requirement for the complicated multiple primers. In conclusion, the sophisticated design principle employed in this work would provide great insight for the development of self-operative isothermal amplifying system enabling short target nucleic acid detection such as microRNAs or any target which is less than 200 mer.

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Digital PCR (polymerase chain reaction) is a powerful and attractive tool for the quantification of nucleic acids. However, the multiplex detection capabilities of this system are limited or require expensive instrumentation and reagents, all of which can hinder multiplex detection goals. Here, we propose strategies toward solving these issues regarding digital PCR. We designed and tested a self-priming digital PCR chip containing 6-plex detection capabilities using monochrome fluorescence, which has six detection areas and four-layer structures. This strategy achieved multiplex digital detection by the use of self-priming to preintroduce the specific reaction mix to a certain detection area. This avoids competition when multiple primer pairs coexist, allowing for multiplexing in a shorter time while using less reagents and low-cost instruments. This also prevents the digital PCR chip from experiencing long sample introduction time and evaporation. For further validation, this multiplex digital PCR chip was used to detect five types of EGFR (epidermal growth factor receptor) gene mutations in 15 blood samples from lung cancer patients. We conclude that this technique can precisely quantify EGFR mutations in high-performance diagnostics. This multiplex digital detection chip is a simple and inexpensive test intended for liquid biopsies. It can be applied and used in prenatal diagnostics, the monitoring of residual disease, rapid pathogen detection, and many other procedures.

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A novel reverse transcription-based loop-mediated isothermal amplification (LAMP) strategy for miRNA detection has been developed. This method consists of two stem-loop probes inspired by the dumbbell-shaped amplicons and inner primers used in conventional LAMP reactions. Termed "terminal hairpin formation and self-priming" (THSP), this reaction incorporates phosphorothioated (PS) modifications to achieve DNA folding and extension without primers. The final signal is monitored by a sequence-specific detection probe, which minimizes the background noise. We suggest that our rapid, facile, and reliable LAMP method will be a promising candidate for detecting miRNA in biomedical applications.

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Reverse transcription-PCR (RT-PCR) is the most widely employed technique for gene expression analysis owing to its high sensitivity, easy reproducibility and fast output. It has been conceived that priming RT reactions with gene-specific primers generates cDNA only from the specific RNA. However, several reports have revealed that cDNA is synthesized even without addition of exogenous primers in RT reactions. Owing to such self-priming activity, the signals from specific strands cannot be accurately detected and can confound the expression analysis, especially in context of overlapping bidirectional transcripts. Here, we demonstrate that purification of biotin-tagged cDNA in conjunction with alkaline denaturation can obviate the problem of background priming and enable accurate strand-specific detection of overlapping transcripts.

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De novo production of RNA on RNA template, a process known as RNA-dependent RNA synthesis, RdRs, and the enzymatic activity conducting it, RNA-dependent RNA polymerase, RdRp, were initially considered to be exclusively virus-specific. Eventually, however, the occurrence of RdRs and the ubiquitous presence of conventional RdRp were demonstrated in numerous eukaryotic organisms. The evidence that the enzymatic machinery capable of RdRs is present in mammalian cells was derived from studies of viruses, such as hepatitis delta virus, HDV, that do not encode RdRp yet undergo a robust RNA replication once inside the mammalian host; thus firmly establishing its occurrence and functionality. Moreover, it became clear that RdRp activity, apparently in a non-conventional form, is constitutively present in most, if not in all, mammalian cells. Because such activity was shown to produce short transcripts, given its apparent involvement in RNA interference phenomena, and because double-stranded RNA is known to trigger cellular responses leading to its degradation, it was generally assumed that its role in mammalian cells is restricted to a regulatory function. However, at the same time, an enzymatic activity capable of generating complete antisense RNA complements of mRNAs was discovered in mammalian cells undergoing terminal differentiation. Moreover, observations of widespread synthesis of antisense RNAs initiating at the 3'poly(A) of mRNAs in human cells suggested an extensive cellular utilization of mammalian RdRp. These results led to the development of a model of RdRp-facilitated and antisense RNA-mediated amplification of mammalian mRNA. Recent detection of the major model-predicted identifiers, chimeric RNA intermediates containing both sense and antisense RNA strands covalently joined in a rigorously predicted and uniquely defined manner, as well as the identification of a putative chimeric RNA end product of this process, validated the proposed model. The results corroborating mammalian RNA-dependent mRNA amplification were obtained in vivo with cells undergoing terminal erythroid differentiation and programmed for only a short survival span. This raises a question of whether mammalian RNA-dependent mRNA amplification is a specialized occurrence limited to extreme circumstances of terminal differentiation or a general physiological phenomenon. The present study addresses this question by testing for the occurrence of RNA-dependent amplification of mRNA encoding extracellular matrix proteins abundantly produced throughout the tissue and organ development and homeostasis, an exceptionally revealing indicator of the range and scope of this phenomenon. We report here the detection of major identifiers of RNA-dependent amplification of mRNA encoding α1, ß1, and γ1 chains of laminin in mouse tissues producing large quantities of extracellular matrix proteins. The results obtained warrant reinterpretation of the mechanisms involved in ubiquitous and abundant production and deposition of extracellular matrix proteins, confirm the occurrence of mammalian RNA-dependent mRNA amplification as a new mode of genomic protein-encoding information transfer, and establish it as a general physiological phenomenon.

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Growing concern about the effect of hydrochloric acid gas (HCl) on environment and abatement of it is now a very serious issue. This present paper is focused on developing a realistic model in order to remove the HCl from the off gases using self-priming venturi scrubber. A detailed parametric study of throat gas velocity (36-72 m/s), liquid level in outer cylinder (0.40-0.77 m) and inlet concentration of HCl (100-500 ppm) on HCl removal efficiency have been done with normal water as a scrubbing liquid. Also the removal efficiency was enhanced by using NaOH solution as a scrubbing liquid in submerged and non-submerged conditions. Therefore, the maximum removal efficiency of HCl was obtained as 87.83% with normal water and 92.54% with 0.005N NaOH solution as the scrubbing liquid at inlet HCl concentration of 500 ppm, throat gas velocity of 60 m/s and liquid level of 0.77 m in submerged condition. Experimental results were validated with the developed empirical model and showed excellent agreement with less deviation.

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Geoffrey Harris, while still a medical student at Cambridge, was the first researcher (1937) to provide experimental proof for the then tentative view that the anterior pituitary gland was controlled by the CNS. The elegant studies carried out by Harris in the 1940s and early 1950s, alone and in collaboration with John Green and Dora Jacobsohn, established that this control was mediated by a neurohumoral mechanism that involved the transport by hypophysial portal vessel blood of chemical substances from the hypothalamus to the anterior pituitary gland. The neurohumoral control of anterior pituitary secretion was proved by the isolation and characterisation of the 'chemical substances' (mainly neuropeptides) and the finding that these substances were released into hypophysial portal blood in a manner consistent with their physiological functions. The new discipline of neuroendocrinology - the way that the brain controls endocrine glands and vice versa - revolutionised the treatment of endocrine disorders such as growth and pubertal abnormalities, infertility and hormone-dependent tumours, and it underpins our understanding of the sexual differentiation of the brain and key aspects of behaviour and mental disorder. Neuroendocrine principles are illustrated in this Thematic Review by way of Harris' major interest: hypothalamic-pituitary-gonadal control. Attention is focussed on the measurement of GnRH in hypophysial portal blood and the role played by the self-priming effect of GnRH in promoting the onset of puberty and enabling the oestrogen-induced surge or pulses of GnRH to trigger the ovulatory gonadotrophin surge in humans and other spontaneously ovulating mammals.

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The occurrence of the primer-independent cDNA synthesis during RT-PCR analysis of human and animal RNA viruses has been well documented. Conversely, there is scant knowledge about this event in plant RNA viruses. Here we show that the primer-independent cDNA synthesis occurs in all eight different plant RNA viruses tested in this study, suggesting a common phenomenon for RT-PCR analysis of plant RNA viruses. Additional experiments indicate that the event is likely contributed to by RNA self-priming, and can be effectively reduced or eliminated through increasing temperature of the RT reaction.

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BACKGROUND: The purpose of this study was to compare the microleakage of traditional composite (Charisma/Gluma Comfort Bond) and self-priming resin (Embrace Wetbond). MATERIALS AND METHODS: Standardized Class V cavities partly in enamel and cementum were prepared in 20 extracted human premolars. Teeth were divided into two groups. Group 1 was restored with Charisma/Gluma Comfort Bond and Group 2 with Embrace Wetbond. The specimens were stored in distilled water at room temperature for 24 h and then subjected to 200 thermocycles at 5°C and 55°C with a 1 min dwell time. After thermocycling teeth were immersed in a 0.2% solution of methylene blue dye for 24 h. Teeth were sectioned vertically approximately midway through the facial and lingual surfaces using a diamond saw blade. Microleakage was evaluated at enamel and cementum surfaces using 10 × stereomicroscope. The statistical analysis was performed using Wilcoxon signed-rank test. RESULTS: Wetbond showed less microleakage at occlusal and gingival margins as compared with Charisma/Gluma Comfort Bond and the results were statistically significant (P < 0.05). CONCLUSION: Class V cavities restored with Embrace Wetbond with fewer steps and fewer materials offers greater protection against microleakage at the tooth restorative interface.

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We present a design for a miniature self-priming peristaltic pump actuated with a single linear actuator, and which can be manufactured using conventional materials and methods. The pump is tolerant of bubbles and particles and can pump liquids, foams, and gases. We explore designs actuated by a motor (in depth) and a shape memory alloy (briefly); and briefly present a manually actuated version. The pump consists of a Delrin acetal plastic body with two integrated valves, a flexible silicone tube, and an actuator. Pumping is achieved as the forward motion of the actuator first closes the upstream valve, and then compresses a section of the tube. The increased internal pressure opens a downstream burst valve to expel the fluid. Reduced pressure in the pump tube allows the downstream valve to close, and removal of actuator force allows the upstream valve and pump tube to open, refilling the pump. The motor actuated design offers a linear dependence of flow rate on voltage in the range of 1.75-3 V. Flow rate decreases from 780 µl/min with increasing back pressure up to the maximum back pressure of 48 kPa. At 3 V and minimum back pressure, the pump consumes 90 mW. The shape memory alloy actuated design offers a 5-fold size and 4-fold weight reduction over the motor design, higher maximum back pressure, and substantial insensitivity of flow rate to back pressure at the cost of lower power efficiency and flow rate. The manually actuated version is simpler and appropriate for applications unconstrained by actuation distance.

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The purpose of this study was to compare and to evaluate the combination use of 5 kinds of dentin adhesive systems and 5 kinds of composite resins using micro-shear bond test. Five adhesive systems (Prime & Bond NT (PBN), Onecoat bond (OC), Excite (EX), Syntac (SY), Clearfil SE bond (CS)) and five composite resins (Spectrum (SP), Synergy Compact (SC), Tetric Ceram (TC), Clearfil AP-X (CA), Z100 (Z1)) were used for this study (5 x 5 = 25group, n = 14/group). The slices of horizontally sectioned human tooth were bonded with each bonding system and each composite resin, and tested by a micro-shear bond strength test. These results were analyzed statistically. The mean micro-shear bond strength of dentin adhesive systems were in order of CS (22.642 MPa), SY (18.368 MPa), EX (14.599 MPa), OC (13.702 MPa), PBN (12.762 MPa). The mean bond strength of self-etching primer system group (CS, SY) in dentin was higher than that of self-priming adhesive system groups (PBN, EX, OC) significantly (P<0.05). The mean bond strength of composite resins was in order of SP (19.008 MPa), CA (17.532 MPa), SC (15.787 MPa), TC (15.068 MPa), Z1 (14.678 MPa). Micro-shear bond strength of SP was stronger than those of other composite resins significantly (P < 0.05). And those of TC and Z1 were weaker than other composite resins significantly (P < 0.05). No difference was found in micro-shear bond strength of composite resin in self-etching primer adhesive system groups (CS, SY) statistically. However, there was significant difference of micro-shear bond strength of composite resin groups in self-priming adhesive systems group (PBN, EX, OC). The combination of composite resin and dentin adhesive system recommended by manufacturer did not represent positive correlation. It didn't seem to be a significant factor.

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