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This study conducted sterilization testing under different conditions using different strains for sterilization and crushing, the intermediate healthcare waste treatment phase, and proposed strategies for diversifying corresponding facilities in addition to promoting their installation. Five indicator microorganisms were selected to test the sterilization efficiency of steam, microwave, and chemical methods. Steam sterilization testing was conducted in accordance with legal and technological standards, microwave testing was carried out according to the legal standard, and chemical sterilization employed three typical compounds. Steam and microwave sterilization achieved 99.9999 % inactivation rates for all five strains under both conditions used; whereas under the chemical sterilization analyses, sodium hypochlorite (1000 ppm) failed to meet the inactivation requirement of the fungal strain Candida albicans, requiring further investigation. Based on these findings, this study presents strategies for diversifying sterilization·crushing facilities and promoting their installation.

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The qualities of precooked foods can be significantly changed by the microorganisms produced during room temperature storage. This work assessed the effects of different antibacterial treatments (CK, without any treatment; microwave treatment, MS; microwave treatment and biological preservatives, MSBP) on the physicochemical properties and microbial communities of precooked crayfish tails during room temperature storage. Only the combination of microwave sterilization and biological preservatives significantly inhibited spoilage, as evidenced by the total viable count (4.15 log CFU/g) after 3 days of room temperature storage, which satisfied the transit time of most logistics companies in China. Changes in pH and TVB-N were also significantly inhibited in the MSBP group compared with those in the CK and MS groups. More than 30 new volatile compounds were produced in the CK groups during room temperature storage. However, in the MSBP groups, the volatile compounds were almost unchanged. The correlations between the microbial composition and volatile compounds suggested that specific bacterial species with metabolic activities related to amino acid, energy, cofactor, and vitamin metabolism, as well as xenobiotics biodegradation and metabolism, were responsible for the changes in volatile compounds. These bacteria included Psychrobacter, Arthrobacter, Facklamia, Leucobacter, Corynebacterium, Erysipelothrix, Devosia, Dietzia, and Acidovorax. Overall, our findings provide a foundation for the development of strategies to inhibit spoilage in precooked crayfish tails stored at room temperature.

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Periodontological grafts are materials used in dentistry to regenerate lost gingival soft tissues or bone parts. In the case of direct contact with blood, the possibility of disease transmission from the source to the patient is high. This source can be an animal or a human. Therefore, the sterilization of grafts before implanting to the patient is of significant importance. The purpose of this study was to evaluate gamma radiation and microwave sterilization processes from microbiological and sterility perspectives and to compare the effectiveness of these two sterilization methods. Grafts were irradiated with 2, 4, 5, 10, 25 and 50 kGy doses of gamma radiation. Another group of same materials was irradiated by microwave for 1, 2, 3 and 4 min at 24,500 MHz and 900 W. Gamma radiation and microwave sterilization methods were evaluated as successful at minimum doses as 5 kGy and 3 min, respectively. Both gamma and microwave sterilization successfu lly sterilized periodontological grafts coded as PBG1, HBG1, HL1, PDG1, MBG3, MDG2 and PDG3. Moreover, microwave sterilization can be used as an alternative novel method to gamma radiation sterilization.

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OBJECTIVE: To determine the mechanism of growth inhibition of Aggregatibacter actinomycetemcomitans by Maillard reaction products (MRP). DESIGN: Growth and cell viabilities in the presence or absence of MRP were measured for both the rough and smooth variants of the bacteria. Effects of addition of ferrous and ferric ions on the inhibition of the bacteria by MRP were determined. RESULTS: MRPs decreased the extent of complex formation of Chrome Azurol S with iron suggesting that MRPs can chelate iron effectively. The chelation causes growth inhibition of both the rough and smooth strains. At low concentrations of the inhibitor, lag time was extended by approximately 12 h while at high concentrations, cells were killed, decreasing cell viability by up to 8 orders of magnitude. Growth of both the rough and smooth strains could be restored to original level by addition of iron. For the rough strain, both ferrous and ferric ions could relieve the inhibition by MRP while for the smooth strain only ferrous ion was effective. CONCLUSION: MRPs inhibit the growth of A. actinomycetemcomitans by chelating iron and the inhibition can be relieved by addition of iron.

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The U.S. Army and NASA need ready-to-eat meals with extended shelf-life for military operations and future manned space missions. For traditional heat sterilization methods, aluminum foil laminated pouches are used to achieve a shelf-life of 3 to 5 years at room temperature. However, those packages are not suited for advanced thermal processing technologies based on microwave energy. This research investigated the effect of polymeric packaging materials on storage stability of garlic flavor, vitamin C, and color of garlic mashed potatoes processed with microwave-assisted thermal sterilization (MATS) technology. Three types of high-barrier metal oxide-coated polymer pouches were used for MATS process, designed to achieve lethality approximately F0 = 6 min. Aluminum foil-based pouches were used for retort process as control. Results demonstrated that both oxygen and water vapor barrier properties (oxygen transmission rate [OTR] and water vapor transmission rate [WVTR]) of the polymer pouches were affected by MATS processing. OTR increased by three to nine times, while WVTR increased by 5 to 20 times after processing. The MATS process resulted in 13% to 16% vitamin C loss, while retort process resulted in 18% loss in garlic mashed potato. The kinetics of vitamin C indicated that metal oxide-coated high-barrier packages (after processing OTR <0.1 cc/m2 .day; WVTR <1.0 g/m2 .day) could replace aluminum foil-based pouches for MATS processed shelf-stable ready-to-eat garlic mashed potatoes. PRACTICAL APPLICATION: Garlic mashed potatoes in polymer packages processed in a microwave-assisted thermal sterilization (MATS) system had better retention of vitamin C compared to samples packaged in aluminum laminated pouches and processed in retort. Polymer packages combined with MATS processing could potentially provide safe, better quality, and nutritious shelf-stable food products for military and space missions.

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The objective of this study was to reduce the microorganism number and salt content in pehtze by microwave sterilization. The maturation time and quality of low-salt sufu were evaluated. The microorganism inactivation rate, moisture content and water activity of the pehtze, which was used for the growth of the starter culture, showed that 4,250 W for 30 s was suitable for the preparation of low-salt sufu. With regard to the physicochemical properties of sufu, 120-day sufu samples obtained by traditional high-salt (14%) fermentation and 75-day sufu samples obtained by low-salt (4%) fermentation met the standard requirements. With regard to the sensory characteristics of sufu, the taste and after taste scores of 75-day low-salt sufu samples were significantly higher than those of 120-day high-salt sufu samples (p < .05).The overall acceptance score of low-salt sufu samples also was higher than that of high-salt sufu samples. The contents of free amino acids and the profiles of typical flavor compounds partly explained the sensory quality and shorter ripening time of sufu manufactured. The total biogenic amine contents were reduced by 46%.

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AIM: The aim of the present study was to evaluate the effect of chemical disinfection, autoclave, and microwave sterilization on some of the key properties of elastomers. METHODS: Five polyvinylsiloxane elastomeric impression materials were evaluated. Forty samples were fabricated from each material. The samples were randomly selected and assigned to four experimental groups with 50 samples each: group I, control; group II,chemical disinfection; group III, autoclave sterilization; and group IV, microwave sterilization. The differences in the mean values were contrasted and compared with the control group and analyzed using two-way analysis of variance (P < 0.05). RESULTS: The results showed that chemical disinfection and autoclave sterilization had no significant effect on the tensile strength and surface roughness, whereas microwave sterilization showed a statistically-significant reduction in tensile strength, and an increase in surface roughness. None of the disinfection and sterilization techniques had a significant effect on wettability. However, autoclave and microwave sterilization resulted in an increase in hydrophilicity of all the materials tested. CONCLUSION: Chemical disinfection and autoclave sterilization had no statistically-significant effect on the tested properties of elastomers, thus autoclave sterilization can be considered as an alternative and an effective mode of disinfection and sterilization to eliminate all forms of disease causing microorganisms from dental impressions.

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Compared with traditional drying methods for Chinese materia medica, microwave drying technology is not only with the features of easy and convenient to operate, rapidity, good effects, well remained appearance of medicine and low energy consumption, but also with the feature of extraordinary sterilization effects at the same time with drying. This article introduced the features and effects of microwave drying and sterilization technology, reviewed its application in the TCM field, and proposed existing problems and prospects in the recent research by targeting security problems (microwave radiation and microwave residue).

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Compared with traditional drying methods for Chinese materia medica, microwave drying technology is not only with the features of easy and convenient to operate, rapidity, good effects, well remained appearance of medicine and low energy consumption, but also with the feature of extraordinary sterilization effects at the same time with drying. This article introduced the features and effects of microwave drying and sterilization technology, reviewed its application in the TCM field, and proposed existing problems and prospects in the recent research by targeting security problems (microwave radiation and microwave residue).

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AIMS: To evaluate and compare the flexural strength and impact strength of conventional and microwave cured denture base resins before and after repeated sterilization using microwave energy to consider microwave curing as an alternative to the conventional method of sterilization. MATERIALS AND METHODS: The conventional heat cure acrylic resin (DPI heat cure material) Group A and microwave-polymerized acrylic resin (Vipi Wave Acrylic resin) Group B were used to fabricate 100 acrylic resins samples using a standard metal die of (86 mm × 11 mm × 3 mm) dimensions. The criterion was flexural strength and impact strength testing which had Group A and Group B samples; 50 samples for flexural strength and 50 samples for impact strength measurement. For each criterion, five control samples were taken for Group A and Group B. The samples were stored in water before experimenting. The test samples were subject to four cycles of microwave sterilization; followed by flexural strength testing with a 3-point flexural test in universal testing machine (UNITEK 94100) and impact strength testing with impact testing machine (ENKAY Pr09/E1/16). RESULTS: The physical properties had significant changes for conventionally cured denture base resins, whereas no changes found for microwave-cured resins after repeated sterilization cycles.

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To observe the effects of Atractylodis Macrocephale Rhizoma processed by different methods (sulfur-fumigation, different temperatures baking and microwave sterilization) on salivary amylase and D-xylose excretion rate in spleen deficiency rats. The rats were divided into blank control group, rhubarb-induced spleen deficiency model control group, and Atractylodis Macrocephale Rhizoma experimental groups processed with different methods. Amylase colorimetric method was used to determine the activities of salivary amylase and D-xylose excretion rate was measured with O-benzylamine method. Then the correlation of salivary amylase activity and D-xylose excretion rate in urinary was analyzed. As compared with blank control group, Atractylodis Macrocephale Rhizoma baked at 100,110 ℃ can increase the unit content of rat salivary amylase and D-xylose excretion rate, with a significant difference (P<0.05). As compared with the model group, Atractylodis Macrocephale Rhizoma baked at 70 ℃ and Atractylodis Macrocephale Rhizoma with microwave treatment had stronger effects than the others, with statistically significant differences (P<0.01). Atractylodis Macrocephale Rhizoma could improve D-xylose absorption function and salivary amylase activity in spleen deficiency rats. In addition, D-xylose excretion rate in urine was positively correlated with salivary amylase activity. Atractylodis Macrocephale Rhizoma processed with different temperatures baking and microwave sterilization had little impact on salivary amylase activity and D-xylose excretion rate in urine of spleen deficiency rats, while sulfur fumigation had great effects on the above two indexes.

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To observe the effects of Atractylodis Macrocephale Rhizoma processed by different methods (sulfur-fumigation, different temperatures baking and microwave sterilization) on salivary amylase and D-xylose excretion rate in spleen deficiency rats. The rats were divided into blank control group, rhubarb-induced spleen deficiency model control group, and Atractylodis Macrocephale Rhizoma experimental groups processed with different methods. Amylase colorimetric method was used to determine the activities of salivary amylase and D-xylose excretion rate was measured with O-benzylamine method. Then the correlation of salivary amylase activity and D-xylose excretion rate in urinary was analyzed. As compared with blank control group, Atractylodis Macrocephale Rhizoma baked at 100,110 ℃ can increase the unit content of rat salivary amylase and D-xylose excretion rate, with a significant difference (P<0.05). As compared with the model group, Atractylodis Macrocephale Rhizoma baked at 70 ℃ and Atractylodis Macrocephale Rhizoma with microwave treatment had stronger effects than the others, with statistically significant differences (P<0.01). Atractylodis Macrocephale Rhizoma could improve D-xylose absorption function and salivary amylase activity in spleen deficiency rats. In addition, D-xylose excretion rate in urine was positively correlated with salivary amylase activity. Atractylodis Macrocephale Rhizoma processed with different temperatures baking and microwave sterilization had little impact on salivary amylase activity and D-xylose excretion rate in urine of spleen deficiency rats, while sulfur fumigation had great effects on the above two indexes.

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OBJECTIVE: This study was designed to evaluate the efficiency of microwave sterilization of orthodontic instruments and molar bands immersed in plain distilled water with and without oral rinse, and to ascertain the minimum time of exposure required to sterilize. MATERIALS AND METHODS: The orthodontic instruments (hinged and nonhinged), molar bands and mouth mirrorsused in the patient 's mouth were selected for the study. The instruments were divided into two groups - Group I with oral rinse-set A (0.01% chlorhexidine gluconate) and set B (0.025% betadine) and Group II (included sets C and D without oral rinse). The instruments of set A, B and C were microwaved at 2,450 MHz, 800 W for 5 min, whereas, set D was microwaved for 10 min at the same above mentioned specifications. The efficacy of sterilization was assessed by stab inoculation of the instruments onto trypticase soya agar plates. The plates were checked for bacterial growth following incubation at 37 °C for 24 h. For sterility control,Geobacillus stearothermophilus (MTCC 1518) was included. RESULTS: No growth was observed in the plates that were inoculated with the microwaved orthodontic instruments of sets A, B and D, whereas scanty bacterial growth was observed in the plates inoculatedwith the microwaved set C instruments. CONCLUSION: Effective sterilization was achieved when the orthodontic instruments and molar bands were immersed in distilled water without oral rinse and microwaved for 10 min as also for those that were immersed in distilled water with oral rinse and microwaved for 5 min.

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Fast reactions mediated by microwaves are often attributed by many to non-thermal effect. We show here that rapid formation of Maillard reaction products during microwave sterilization of growth medium results from concentration effect and not any non-thermal effect. This leads to an improved method for microwave sterilization of growth media.

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