Male reproductive function before and after the adjustment of the COVID-19 prevention policy: a multicenter study in China.

At the end of 2022, the adjustment of the coronavirus disease 2019 (COVID-19) pandemic control policy in China resulted in a large-scale increase in public infection. To compare the fertility parameters of male patients before and after the adjustments of the COVID-19 pandemic control policy in China, we collected data on patients' medical histories and laboratory examinations on their first visits between June 2022 and March 2023 in five different hospitals. Data were divided into five groups according to the timeline of the policy adjustment. The data we collected from male patients included semen quality and serum reproductive hormone levels, and intergroup comparisons were made using the Mann-Whitney U and Chi-square tests. In total, 16 784 cases underwent regular semen analysis, 11 180 had sperm morphology assessments, and 7200 had reproductive hormone analyses. The data showed declining trends in semen volume, sperm motility, and the progressive sperm motility rate after the policy adjustment. Subgroup comparison revealed an initial decrease and gradual recovery in progressive motility rate. Sperm morphology analysis showed increased neck and tail abnormalities after the policy adjustment. No significant change in hormone levels was observed. Following the adjustment of the COVID-19 prevention policy in China, a decline in sperm motility and morphology was observed. This trend may gradually recover over 2 months. After the policy adjustment, reproductive hormone levels were relatively stable throughout, except for an increase in luteinizing hormone (LH). These changes in semen parameters suggest that the policy adjustment had a short- to medium-term impact on male reproductive function.

Magnesium ions improving the growth and organics reduction of Rhodospirillum rubrum cultivated in sewage through regulating energy metabolism pathways.

Rhodospirillum rubrum has the potential for biomass resource recycling combined with sewage purification. However, low biomass production and yield restricts the potential for sewage purification. This research investigated the improvement of biomass production, yield and organics reduction by Mg²âº in R. rubrum wastewater treatment. Results showed that with optimal dosage (120 mg/L), biomass production reached 4,000 mg/L, which was 1.5 times of that of the control group. Biomass yield was improved by 43.3%. Chemical oxygen demand (COD) removal reached over 90%. Hydraulic retention time was shortened by 25%. Mechanism analysis indicated that Mg²âº enhanced the isocitrate dehydrogenase and Ca²âº/Mg²âº-ATPase activities, bacteriochlorophyll content on respiration and photophosphorylation. These effects then enhanced ATP production, which led to more biomass accumulation and COD removal. With 120 mg/L Mg²âº dosage, the isocitrate dehydrogenase and Ca²âº/Mg²âº-ATPase activities, bacteriochlorophyll content, ATP production were improved, respectively, by 33.3%, 50%, 67%, 41.3% compared to those of the control group.

[Evaluation indices of greenhouse gas mitigation technologies in cropland ecosystem].

In spite of the increasing studies on greenhouse gas (GHG) emissions mitigation technologies, there is still a lack of systematic indices for evaluation of their overall impacts in croplands. In this study, we collected all the indices relating to greenhouse gas emissions and analyzed each index following the principles of representativeness, objectivity, completeness, dominance and operability. Finally, we proposed evaluation indices for mitigation technologies based on the current situation of China. Crop yield per unit area was proposed as a constrained index, and greenhouse gas emissions intensity, defined as GHG emissions per unit of produced yield, was proposed as comprehensive index to evaluate the greenhouse effect of various croplands mitigation technologies. Calculation of GHG emissions intensity involved yield, change of soil organic carbon, direct N2O emissions, paddy CH4 emissions and direct and indirect emissions from inputs into croplands. By following these evaluation indices, the greenhouse effect of the technologies could be well evaluated, which could provide scientific basis for their further adoption.

Improving the growth of Rubrivivax gelatinosus cultivated in sewage environment.

Rubrivivax gelatinosus cultivated in wastewater environment can combine the biomass resource recycling for generating chemicals with sewage purification. However, low biomass accumulation restricts the exertion of this advantage. Thus, this paper investigated Fe(3+) advancement for biomass production in starch wastewater under light-anaerobic condition. Results showed that addition of Fe(3+) was successful in enhancing biomass production, which certainly improved the feasibility of biomass recycling in R. gelatinosus starch wastewater treatment. With optimal Fe(3+) dosage (20 mg/L), biomass production reached 4,060 mg/L, which was 1.63 times that of control group. Amylase activity was improved by 48 %. Both COD removal and starch removal reached 90 %. Hydraulic retention time was shortened by 25 %. Proper Fe(3+) dosage enhanced biomass production, but excess Fe(3+) was harmful for biomass accumulation.

Strengthening the growth of Rubrivivax gelatinosus in sewage purification through ferric ion regulated photophosphorylation and respiration.

Rubrivivax gelatinosus has the potential of biomass resource recycling combined with sewage purification. However, low biomass production and yield restricts the potential for sewage purification. Thus, this research investigated the improvement of biomass production and yield and organics reduction by Fe(3+) in R. gelatinosus wastewater treatment. Results showed that 10-30 mg/L Fe(3+) improved biomass yield in wastewater to a level found in culture medium. With optimal dosage (20 mg/L), biomass production reached 4,300 mg/L, which was 1.67 times that of the control group. Biomass yield was improved by 43.3%. Chemical oxygen demand (COD) removal reached above 91%. Hydraulic retention time was shortened by 25%. Mechanism analysis indicated that Fe(3+) enhanced the succinate and NADH dehydrogenase activities and, bacteriochlorophyll content in three energy metabolism pathways. These effects then enhanced adenosine triphosphate (ATP) production, which led to more biomass accumulation and COD removal. With 20 mg/L Fe(2+) dosage, succinate and NADH dehydrogenase, coproporphyrinogen III oxidase activities, bacteriochlorophyll content and ATP production were improved, respectively, by 48.4, 50.8, 50, 67 and 56% compared to those of the control group.

[Phosphorus removal characteristics by aerobic granules in normal molasses wastewater after anaerobic treatment].

COD decreased obviously in normal molasses wastewater after anaerobic treatment, however, concentrations of nitrogen and phosphorus were still higher in the effluent which seriously damaged the ecological balance. In this study, aerobic granules cultivated in sequencing batch airlift reactor (SBAR) were carried out for treating the effluent; phosphorus removal processes and characteristics were discussed as well. The mean diameter of aerobic granules cultivated by multiple carbon sources (acetate, propionate and butyrate) was 1.7 mm. The average phosphorus removal efficiency was 90.9% and the level of phosphorus in effluent was only 1.3 mg x L(-1); TP released per COD consumed was 0.571 and the specific rate of TP released was 5.73 mg x (g x h)(-1). NO3(-) -N usage of phosphorus accumulating organisms (PAOs) improved during denitrifying process because the concentration of propionate and butyrate increased in multiple carbon sources which means the phosphorus uptake efficiency increased when per NO3(-) -N consumed. Phosphorus content represented a stronger correlation with magnesium, calcium and ferrum contents in aerobic granules and their extracellular polymeric substances (EPS), the phosphorus adsorption by EPS could enhance phosphorus removal. 61.9% of phosphorus accumulating organisms were denitrifying phosphorus accumulating organisms in aerobic granules and TP uptake per NO3(-) -N consumed was 1.14 which was higher than that of aerobic granules only cultivated by acetate.

Fermentative hydrogen production from soybean protein processing wastewater in an anaerobic baffled reactor (ABR) using anaerobic mixed consortia.

Fermentative H(2) production from soybean protein processing wastewater (SPPW) was investigated in a four-compartment anaerobic baffled reactor (ABR) using anaerobic mixed cultures under continuous flow condition in the present study. After being inoculated with aerobic activated sludge and operated at the inoculants of 5.98 gVSS L(-1), COD of 5000 mg L(-1), HRT of 16 h and temperature of (35 ± 1) °C for 22 days, the ABR achieved stable ethanol-type fermentation. The specific hydrogen production rate of anaerobic activated sludge was 165 LH(2)kg MLVSS(-1) day(-1), the substrate conversion rate was 600.83 LH(2)kg COD(-1)and the COD removal efficiency was 44.73% at the stable operation status. The ABR system exhibited a better stability and higher hydrogen yields than continuous stirring tank reactor under the same operational condition. The experimental data documented the feasibility of substrate degradation along with molecular H(2) generation utilizing SPPW as primary carbon source in the ABR system.

[Capability and bacteria community analysis of an anaerobic baffled reactor treating soybean wastewater].

Capability and process characteristic of anaerobic baffled reactor (ABR) treating soybean wastewater were investigated in a 4-compartment ABR with an effective volume of 28 L. During an operation period of 100 days, the organic loading rate (OLR) increased by stages and its influence on the chemical oxygen demand (COD) removal efficiency was researched. The bacteria community structures in anaerobic activated sludge from different stages were also investigated by single-strand conformation polymorphism (SSCP) with the eubacterium universal primers SRV3-2P and BSF8/20, while the microbial genetic distance being analyzed by UPGMA communities clustering method. With an inoculated aerobic activated sludge of 18.0 g x L(-1) in terms of mixed liquor volatile suspend solid (MLVSS), the reactor started up at COD concentration of 2000 mg/L, hydraulic retention time (HRT) of 39.5 h and temperature of (35 +/- 1) degrees C for 31 d, the ABR achieved a stable state that resulted in 96% COD removal. When OLR increased stage by stage from 1.2 kg x (m3 x d)(-1) to 6.0 kg x (m3 x d)(-1), the reactor could performed steadily with a COD removal efficiency as high as 98%, and this indicated that compartmentalized ABR held a good performance during shock loadings. It was found that a step change in OLR had a remarkably effect on the structure and distribution of microbial communities in each compartment. With the organic loading rate increase, the genetic distances among the microbial communities in the compartments extended gradually, indicating that the specificity of microbial communities in each compartment was enhanced.

The performance and phase separated characteristics of an anaerobic baffled reactor treating soybean protein processing wastewater.

A laboratory-scale anaerobic baffled reactor (ABR) with four compartments using soybean protein processing wastewater as organic loading rates (OLRs) was investigated for the performance and phase separated characteristics. It was found that the chemical oxygen demand (COD) removal efficiencies were 92-97% at 1.2-6.0kgCOD/m3d feeding. The dominated species, propionate and butyrate, were found in the 1st compartment. Acetate was dominated in the 2nd compartment and then decreased in the 3rd and 4th. Meanwhile, 93% volatile fatty acids (VFAs) were removed in the 3rd and 4th compartments. In the 1st compartment, biogas revealed carbon dioxide (CO2) and hydrogen (H2). The highest H2 yield was found in the 2nd compartment, thereafter decreased from the 2nd to 4th which corresponded to the increased of the methane (CH4) yield. It indicated that the proper anaerobic consortium in each separate compartment was developed along with substrate availability and specific environmental conditions.

[Bioaugmentation of hydrogen producing bacteria on operation of bio-hydrogen producing reactor].

Hydrogen producing strain Ethanoligenens sp. B49 was inoculated into activated sludge of continuous stirred tank reactor (CSTR)to bioaugment hydrogen production. Hydrogen production capacities, compositions of fermentation products and pH value before and after bioaugmentation were investigated. When organic loading rate was 12 kg/(m3 x d), bioaugmentation of hydrogen producing strain enhanced hydrogen production rate and improved the composition of fermentation products significantly. After bioaugmentation, hydrogen production rate increased from 3.6 mmol/(kg x d) to 5.7 mmol/(kg x d), which was 1.5 times as that before bioaugmentation. Before bioaugmentation, average concentration of ethanol, acetic acid and propionic acid were 6.8 mmol/L, 5.3 mmol/L, 4.8 mmol/L respectively, while after bioaugmentation, those were 10.5 mmol/L, 7.5 mmol/L and 1.7 mmol/L respectively. Ethanol and acetic acid accounted for 86.8% in total fermentative products after bioaugmentation, while only 72% before bioaugmentation. pH value of effluent dropped from 4.5-4.7 to 4.3. Bioaugmentation of hydrogen producing strain is helpful to promote the formation of ethanol-type fermentation in low organic loading rate.

Molecular characterization and hydrogen production of a new species of anaerobe.

For the fermentative hydrogen production process with carbohydrates, isolation and identification of hydrogen-producing bacteria (HPB) with high yield and high evolution rate are very important. Improved Hungater rolling tube technique and plate method of culture bottle (PMCB) were used to enumerate and isolate the HPB. The HPB-Li and Ren (HPB-LR) medium was designed to inoculate and isolate HPB under temperature of 37 degrees C and pH of 4.0-6.7. In this study, an isolate of HPB with high yield and high evolution rate was isolated, named Rennanqilyf3 (R3), which is a gram-positive, straight rod, non-spore forming, encapsulated, strict anaerobe, with long peritrichous flagella and three to four metachromatic granules. It performs ethanol-type fermentation, and glucose is its optimum carbon source for hydrogen production. The 16S rDNA sequencing of the R3 isolate indicated that it might be a new species. The hydrogen production capacity of the R3 isolate varied with the glucose concentration and pH. The optimum glucose concentration was 12.0 g/L (with H2 yield of 58.6 mmolH2/L-culture) and the optimum initial pH was 5.5 (with H2 yield of 34.2 mmolH2/L-culture). The maximum rate of cell proliferation were 0.46 and 0.63 g/L when glucose concentration was 15.0 g/L and pH was 5.5, respectively. The maximum yields of ethanol and acetic acid were achieved when the glucose concentration was 12.0 g/L and the pH was 5.5.