Diversity of Microbial Functional Genes Promotes Soil Nitrogen Mineralization in Boreal Forests.

Soil nitrogen (N) mineralization typically governs the availability and movement of soil N. Understanding how factors, especially functional genes, affect N transformations is essential for the protection and restoration of forest ecosystems. To uncover the underlying mechanisms driving soil N mineralization, this study investigated the effects of edaphic environments, substrates, and soil microbial assemblages on net soil N mineralization in boreal forests. Field studies were conducted in five representative forests: Larix principis-rupprechtii forest (LF), Betula platyphylla forest (BF), mixed forest of Larix principis-rupprechtii and Betula platyphylla (MF), Picea asperata forest (SF), and Pinus sylvestris var. mongolica forest (MPF). Results showed that soil N mineralization rates (Rmin) differed significantly among forests, with the highest rate in BF (p < 0.05). Soil properties and microbial assemblages accounted for over 50% of the variability in N mineralization. This study indicated that soil environmental factors influenced N mineralization through their regulatory impact on microbial assemblages. Compared with microbial community assemblages (α-diversity, Shannon and Richness), functional genes assemblages were the most important indexes to regulate N mineralization. It was thus determined that microbial functional genes controlled N mineralization in boreal forests. This study clarified the mechanisms of N mineralization and provided a mechanistic understanding to enhance biogeochemical models for forecasting soil N availability, alongside aiding species diversity conservation and fragile ecosystem revitalization in boreal forests.

Temporal-Spatial Fluctuations of a Phytoplankton Community and Their Association with Environmental Variables Based on Classification and Regression Tree in a Shallow Temperate Mountain River.

The effects of environmental factors on phytoplankton are not simply positive or negative but complex and dependent on the combination of their concentrations in a fluctuating environment. Traditional statistical methods may miss some of the complex interactions between the environment and phytoplankton. In this study, the temporal-spatial fluctuations of phytoplankton diversity and abundance were investigated in a shallow temperate mountain river. The machine learning method classification and regression tree (CART) was used to explore the effects of environmental variables on the phytoplankton community. The results showed that both phytoplankton species diversity and abundance varied fiercely due to environmental fluctuation. Microcystis aeruginosa, Amphiprora sp., Anabaena oscillarioides, and Gymnodinium sp. were the dominant species. The CART analysis indicated that dissolved oxygen, oxidation-reduction potential, total nitrogen (TN), total phosphorus (TP), and water temperature (WT) explained 36.00%, 13.81%, 11.35%, 9.96%, and 8.80%, respectively, of phytoplankton diversity variance. Phytoplankton abundance was mainly affected by TN, WT, and TP, with variance explanations of 39.40%, 15.70%, and 14.09%, respectively. Most environmental factors had a complex influence on phytoplankton diversity and abundance: their effects were positive under some conditions but negative under other combinations. The results and methodology in this study are important in quantitatively understanding and exploring aquatic ecosystems.

A New Methodology for High Spatiotemporal Resolution Measurements of Air Volatile Organic Compounds: From Sampling to Data Deconvolution.

Monitoring of volatile organic compounds (VOCs) in air is crucial for understanding their atmospheric impacts and advancing their emission reduction plans. This study presents an innovative integrated methodology suitable for achieving semireal-time high spatiotemporal resolution three-dimensional measurements of VOCs from ground to hundreds of meters above ground. The methodology integrates an active AirCore sampler, custom-designed for deployment from unmanned aerial vehicles (UAV), a proton-transfer-reaction mass spectrometry (PTR-MS) for sample analysis, and a data deconvolution algorithm for improved time resolution for measurements of multiple VOCs in air. The application of the deconvolution technique significantly improves the signal strength of data from PTR-MS analysis of AirCore samples and enhances their temporal resolution by 4 to 8 times to 4-11 s. A case study demonstrates that the methodology can achieve sample collection and analysis of VOCs within 45 min, resulting in >120-360 spatially resolved data points for each VOC measured and achieving a horizontal resolution of 20-55 m at a UAV flight speed of 5 m/s and a vertical resolution of 5 m. This methodology presents new possibilities for acquiring 3-dimensional spatial distributions of VOC concentrations, effectively tackling the longstanding challenge of characterizing three-dimensional VOC distributions in the lowest portion of the atmospheric boundary layer.

A Rat Model of Middle Cerebral Artery Occlusion/Reperfusion without Damaging the Anatomical Structure of Cerebral Vessels.

Ischemic stroke stands as the primary cause of long-term disability and mortality among adults worldwide. Animal models of ischemic stroke have significantly contributed to our understanding of its pathological mechanisms and the development of potential treatments. Presently, there are two common methods involving filament (endovascular suture) techniques to induce animal models of cerebral ischemia. However, these methods have inherent limitations, such as reduced blood perfusion to the brain, damage to the external carotid artery system, impaired food and/or water intake, and sensory dysfunction of the face. This article introduces a new method for inducing a rat ischemic stroke model without compromising the cerebral vascular anatomy. In this study, the common carotid artery (CCA) of Sprague-Dawley rats was exposed, and an incision was made. A filament was then inserted through the incision into the internal carotid artery to occlude the middle cerebral artery. After 1.5 h of induced ischemia, the occluding filament was fully removed from both the internal carotid artery and the CCA. The incision in the CCA was subsequently sutured using 11-0 microsurgical sutures under a microscope (magnification 4x). Through the utilization of microsurgical techniques to repair the CCA, this study successfully developed a unique method to induce an ischemic stroke model in rats while preserving the anatomical integrity of cerebral blood vessels.

Effect of out-of-school visual art activities on academic performance. The mediating role of socioeconomic status.

The application of visual art and other extracurricular activities to children's sustainable development is predominantly discussed in Western countries. Consequently, non-Western society could not cherish the benefit of visual art on their children's cognitive and non-cognitive skill development due to a lack of evidence that would revive the community, educators, and policy-makers' impressions about visual art activities, in addition to its amusement use. Thus, the present study adopted a cross-sectional study comprised of a large-scale survey (N = 1624) taken from the southwest part of China to assess the impact of out-of-school visual art activities on children's academic attainment across economically advantaged and disadvantaged children. Astonishingly, the study's findings shed light on current Chinese parents' dedication to purchasing out-of-school activities regardless of their social class difference; notwithstanding, lower-class parents ought to learn that spending time with their children during their activities is more beneficial. The study's implication calls for curriculum policy reform involving aesthetic education and expanding community youth centers for different extracurricular activities.

Unveiling the absorption, translocation, and metabolism of penthiopyrad in pakchoi under hydroponic and soil-cultivated conditions.

The efficient use of pesticides has long been a topic of public concern, necessitating a thorough understanding of their movement in plants. This study investigates the translocation and distribution of penthiopyrad in pakchoi plants cultivated both in hydroponic and soil-cultivated conditions. Results indicate that penthiopyrad predominantly accumulates in the roots, with concentrations of 11.3-53.9 mg/kg following root application, and in the leaves, with concentrations of 2.0-17.1 mg/kg following foliar application. The bioconcentration factor exceeded 1, with values ranging from 1.2 to 23.9 for root application and 6.4 to 164.0 for foliar application, indicating a significant role in the absorption and accumulation processes. The translocation factor data, which were <1, suggest limited the translocations within pakchoi plants. The limitation may be attributed to the hydrophobic properties of penthiopyrad (log Kow = 3.86), as evidenced by its predominant distribution in the subcellular solid fractions of pakchoi tissues, accounting for 93.1% to 99.5% of the total proportion. Six metabolites (753-A-OH, M12, 754-T-DO, M11, PCA, and PAM) were identified in this study as being formed during this process. These findings provide valuable insights into the absorption, translocation, and metabolism of penthiopyrad in pakchoi.

A subcutaneous transplanted tumor mouse model of oral cancer overexpressing miR-181a-5p study of small intestine metabolomics / 中国比较医学杂志

Objective To analyze the effects of miR-181a-5p overexpression on metabolites in the small intestines of mice with subcutaneous oral cancer by detecting changes in metabolites and metabolic pathways.Methods Three groups were included in study:Control group,negative control and miR-181a-5p overexpression group.To establish a subcutaneous oral cancer model in mice,variously treated cell suspensions were subcutaneously injected into the upper right of the groin in female M-NSG severely immunodeficient mice.Changes in pathology and small intestinal tissues were assessed by HE staining.Changes in mouse body weight were also assessed.Tandem orbitrap mass spectrometry and ultra-high performance liquid chromatography-tandem time-of-flight mass spectrometry,were used to examine metabolites in the small intestines.By pre-analyzing the original data and quality rating sample data,XCMS was able to assess which metabolites were different among the groups.To identify unique metabolic pathways,KEGG enrichment analysis was used.Results A total of 170 distinct metabolites were found in the small intestinal tissues of Control and NC groups.Choline metabolism,alanine,aspartate,and glutamate metabolism,GABA synaptic metabolism,glycerophospholipid metabolism,cAMP signaling route,cancer center carbon metabolism,and niacin and niacin amine metabolic pathways were important signaling pathways for metabolite enrichment.In the NC group,16 distinct metabolites with VIP values larger than 2 were found in the small intestines compared with the OE group overexpressing miR-181a-5p.Glycerin phosphorylcholine,palmitic acid,3-hydroxybutyl carnitine,and β-hydroxybutyric acid were among the metabolites that significantly varied.The primary enhanced metabolic pathway was the choline pathway.Conclusions Mouse small intestines underwent slight changes from subcutaneous oral cancer with the greatest effect on metabolites critical for energy metabolism.The choline metabolic pathway was the pathway that selected absolutely metabolites in mouse small intestines with subcutaneous grafts of oral cancer.

Effects of Electroacupuncture on Cyt-C and Caspase-9 Expression in Hippocampal Tissue of Rats with Chronic Pain and Depression Comorbidity / 中国中医药信息杂志

Objective To observe the effects of electroacupuncture(EA)at"Hegu"and"Taichong"on the expressions of cytochrome C(Cyt-C)and Caspase-9 in the hippocampus of rats with chronic pain and depression comorbidity(CPDC);To explore its potential mechanism for the treatment of CPDC.Methods A total of 60 SD rats were randomly divided into sham-operation group,model group,medication group and EA group,with 15 rats in each group.The CPDC model was induced by twice injection of complete Freund's adjuvant into the plantar of the left hind paw.EA group was applied to bilateral"Hegu"and"Taichong"for 20 min,the medication group were treated with duloxetine suspension 10 mg/kg by gavage for 14 days.The mechanical paw withdrawal threshold and thermal withdrawal latency were measured on day 7,14,21 and 28 after the first injection,tail suspension test and sucrose preference test were performed on day 14 and 28,Nissl staining was used to observe hippocampal neurons and the number of Nissl body,the protein expressions of Cyt-C and Caspase-9 in hippocampal tissue were detected by Western blot and immunohistochemistry.Results Compared with the sham-operation group,the mechanical paw withdrawal threshold and thermal withdrawal latency of the model group significantly decreased(P<0.01),the tail suspension immobility time increased(P<0.01),the percentage of sucrose preference decreased(P<0.01),the neurons were thinly arranged,the neurons were damaged and lost,and the number of Nissl body were less(P<0.01),the apoptotic rate of hippocampal neurons increased(P<0.01),the expression of Cyt-C,Caspase-9 and cleaved-Caspase-9/Caspase-9 ratio in hippocampal tissue increased(P<0.01).Compared with the model group,the mechanical paw withdrawal threshold and thermal withdrawal latency of the EA group and medication group significantly increased(P<0.01),the tail suspension immobility time decreased(P<0.01),the percentage of sucrose preference increased(P<0.01),the loss of neurons in hippocampus was reduced,the cells were arranged neatly,and the nucleoli were clear,the number of Nissl body increased(P<0.01),the apoptotic rate of hippocampal neurons decreased(P<0.01),and the expression of Cyt-C,Caspase-9 and cleaved-Caspase-9/Caspase-9 ratio in hippocampal tissue decreased(P<0.01).Conclusion EA at"Hegu"and"Taichong"can alleviate pain and depression in CPDC rats,which may be related to inhibiting the expressions of Cyt-C and Caspase-9 in hippocampal tissue and inhibiting the apoptosis of hippocampal neurons,thus playing a neuroprotective effect.

Exploration and Practice of Curriculum Construction of Biological Clock and Health / 生物化学与生物物理进展

General education in natural sciences is a critical component in higher education. In this article, I introduced the exploration and practice of curriculum construction of “Biological Clock and Health” at Tsinghua University. The course has been open to students for 3 semesters so far. Students who selected the course come from 27 departments of the university. The students provided positive feedbacks after taking this class, including self-report of improved sleep quality and better understanding of the research logic and methods in life sciences. The logic and methods of the construction of “Biological Clock and Health” described in this article provide insights to the construction of other courses in natural sciences of general education.

Optimal timing for early mobilization initiatives in intensive care unit patients: A systematic review and network meta-analysis.

OBJECTIVES: Analyse the effect of varying start times for early exercise interventions on the prevention of intensive care unit-acquired weakness. RESEARCH METHODOLOGY: We conducted a comprehensive search on PubMed, Cochrane Library, Web of Science, Embase, China Biology Medicine Disc, China National Knowledge Infrastructure, Wan Fang Database, and reference lists up to May 2023. SETTING: We systematically searched the literature for all randomized controlled trials on the effect of early mobilization in patients with critical illness. MAIN OUTCOME MEASURES: The primary outcome assessed was the incidence of intensive care unit-acquired weakness. The secondary outcomes included: the Medical Research Council Score, the Barthel Index, duration of mechanical ventilation, length of intensive care unit stay, total length of hospital stay, mortality and incidence of intensive care unit-related complications. RESULTS: The results of meta-analysis showed that compared with routine care, less than 24 hours after admission (RR = 0.44, 95 %CI: 0.28-0.68), more than 24 hours (RR = 0.33, 95 %CI: 0.16-0.67), less than 72 hours after admission (RR = 0.33, 95 %CI: 0.20-0.52) may lead to a lower incidence of intensive care unit-acquired weakness. The results of under surface cumulative ranking showed that early mobilization within 72 hours may have the lowest incidence of intensive care unit-acquired weakness (SUCRA = 81.9 %). CONCLUSIONS: The current empirical evidence from intensive care unit patients suggests that initiating mobilization protocols within 24-72 hours timeframe following admission to the intensive care unit could potentially be the most beneficial strategy to reduce the incidence of intensive care unit-acquired weakness and the related medical complications. Moreover, this strategy seems to significantly improve rehabilitation and treatment outcomes for these patients. IMPLICATIONS FOR CLINICAL PRACTICE: According to this study, medical and nursing staff in the intensive care unit have the chance to identify the most suitable timing for the implementation of early rehabilitative measures for patients. This can potentially prevent intensive care unit-acquired weakness and enhance various clinical outcomes for patients.

Combined analysis of inorganic elements and flavonoid metabolites reveals the relationship between flower quality and maturity of Sophora japonica L.

Flos Sophorae (FS), or the dried flower buds of Sophora japonica L., is widely used as a food and medicinal material in China. The quality of S. japonica flowers varies with the developmental stages (S1-S5) of the plant. However, the relationship between FS quality and maturity remains unclear. Inductively coupled plasma optical emission spectrometry (ICP-OES) and ultra-high performance liquid chromatography coupled with electrospray ionization-triple quadrupole-linear ion trap mass spectrometry (UPLC-ESI-Q TRAP-MS/MS) were used to analyze inorganic elements and flavonoid metabolites, respectively. A combined analysis of the inorganic elements and flavonoid metabolites in FS was conducted to determine the patterns of FS quality formation. Sixteen inorganic elements and 173 flavonoid metabolites that accumulated at different developmental stages were identified. Notably, 54 flavonoid metabolites associated with the amelioration of major human diseases were identified, and Ca, P, K, Fe, and Cu were postulated to influence flavonoid metabolism and synthesis. This study offers a novel perspective and foundation for the further exploration of the rules governing the quality of plant materials.

PE (0:0/14:0), an endogenous metabolite of the gut microbiota, exerts protective effects against sepsis-induced intestinal injury by modulating the AHR/CYP1A1 pathway.

Sepsis is known to cause damage to the intestinal mucosa, leading to bacterial translocation, and exacerbation of both local and remote organ impairments. In the present study, fecal samples were collected from both septic and healthy individuals. Analysis through 16s rRNA sequencing of the fecal microbiota revealed that sepsis disrupts the balance of the gut microbial community. Recent research has highlighted the association of lipid metabolism with disease. By analyzing the fecal metabolome, four lipid metabolites that showed significant differences between the two groups were identified: PE (O-16:0/0:0), PE (17:0/0:0), PE (0:0/14:0), and PE (12:0/20:5 (5Z, 8Z, 11Z, 14Z, 17Z)). Notably, the serum levels of PE (0:0/14:0) were higher in the healthy group. Subsequent in vitro and in vivo experiments demonstrated the protective effects of this compound against sepsis-induced intestinal barrier damage. Label-free proteomic analysis showed significant differences in the expression levels of the aryl hydrocarbon receptor (AHR), a protein implicated in sepsis pathogenesis, between the LPS-Caco-2 and LPS-Caco-2 + PE (0:0/14:0) groups. Further analysis, with the help of Discovery Studio 3.5 software and co-immunoprecipitation assays, confirmed the direct interaction between AHR and PE (0:0/14:0). In the cecal ligation and puncture (CLP) model, treatment with PE (0:0 /14:0) was found to up-regulate the expression of tight junction proteins through the AHR/Cytochrome P450, family 1, subfamily A, and polypeptide 1 (CYP1A1) pathway. This highlights the potential therapeutic use of PE (0:0/14:0) in addressing sepsis-induced intestinal barrier damage.

Antinociceptive effects of carbidopa levodopa on normal rats and Parkinson's disease mice.

Carbidopa levodopa is widely used to ameliorate motor symptoms of Parkinson's disease (PD) patients. Pain is one of common symptoms of PD. The aim of this experiment is to study antinociceptive effects of carbidopa levodopa on normal rats and PD mice. Rats were intragastrically treated with carbidopa levodopa and the hind paw withdrawal latency (HWL) was investigated. PD mouse model was prepared with MPTP and then the antinociceptive effects of carbidopa levodopa on PD mice were evaluated. In normal rats, the HWL to thermal stimulus was augmented after carbidopa levodopa administration (p<0.05 or p<0.01) and carbidopa levodopa increased the HWL (p<0.05 or p<0.01) to mechanical stimulus. In PD mice, carbidopa levodopa elevated the HWL of the thermal stimulus in PD mice (p<0.05). Furthermore, the HWL in the inflammatory pain of PD mice was also increased by carbidopa levodopa treatmet (p<0.01). The current findings indicate that carbidopa levodopa has an antinociceptive effects in normal rats and PD mice. The analgesic effect of carbidopa levodopa on patients with or without PD is worth studying in further research.

Establishment of health related physical fitness evaluation system for school adolescents aged 12-16 in Pakistan: a cross-sectional study.

Background: The decline in adolescent physical fitness is a significant global public health concern, and Pakistan is no exception. The country's absence of a health-related physical fitness (HRPF) evaluation system has compounded this issue. To bridge this gap, this study aims to develop a scientifically-based HRPF evaluation system for the adolescent population that meets international standards. The evaluation system identifies at-risk children and improves adolescent health outcomes, including obesity, cardiovascular and musculoskeletal disorders, chronic diseases, and psychological illnesses, through crucial physical fitness evaluation. This study specifically aims to establish an HRPF evaluation system for school adolescents aged 12-16 in Pakistan. Methods: A cross-sectional study was conducted among 2,970 school adolescents aged 12-16 years in the South Punjab, Pakistan. The study used a stratified sampling technique to select participants. The HRPF evaluation system included four components: cardiorespiratory endurance, core muscular endurance, muscular strength, and body composition. Data were collected through standardized tests and anthropometric measurements. Results: The study's results indicated that the HRPF evaluation scoring system was feasible and valid for evaluating the HRPF of school adolescents in the South Punjab region of Pakistan. The results of the evaluation system categorized participants into five groups based on their performance: excellent (6.2%), good (24.9%), medium (50.7%), poor (17%), and very poor (1.2%). Conclusion: The study establishes an HRPF evaluation system for Pakistani school adolescents. This system lays the foundation for implementing effective strategies to improve their physical health. The findings offer valuable insights to policymakers, health professionals, and educators, enabling them to promote fitness and devise impactful interventions for enhancing HRPF in this population.

Research on the integral forming process of thin walled and thick mouth seamless gas cylinders.

There is a considerable difference in wall thickness between the mouth and the cavity of thin-walled and thick-mouthed seamless gas cylinders, and the existing manufacturing processes are unable to effectively meet product requirements. To overcome such issue, a step-by-step boring-necking-spinning solution for gas cylinders was proposed, in which sufficient wall thickness is reserved for the mouth area of the cylinder blank, followed by necking-spinning to realize the overall forming of thin-walled, thick-mouthed seamless gas cylinders. The stress-strain distribution and geometric dimensional changes of gas cylinders during the spinning process were investigated by means of finite element simulation, and the effects of different process parameters on the stress and wall thickness of the bottle mouth were analyzed. Further, multi-objective optimization of the response surface model was performed using the NSGA-II algorithm to derive a set of optimal process parameters. Finally, the correctness of the simulation and optimization results was verified experimentally, and the expected geometry and optimal strain state of the gas cylinder were obtained. The newly developed processing solution represents a groundbreaking advancement in the manufacturing of thin-walled and thick-mouthed gas cylinders.

Responses of Zooplankton Community Pattern to Environmental Factors along the Salinity Gradient in a Seagoing River in Tianjin, China.

As the primary consumers in aquatic organisms, zooplankton play an important role in aquatic ecosystems. It is valuable for management and researchers to have an insight into the responses of zooplankton community patterns to environmental factors. In this study, RDA and variation partitioning analysis were adopted to determine the important environmental factors affecting zooplankton abundance and biomass, as well as the relative importance of different environmental factors. The findings reveal that TN (total nitrogen), WD (water depth), pH, and SAL (salinity) were all important abiotic factors shaping the zooplankton community pattern in the study area. TN affected protozoa by influencing Stentor amethystinus, while the effects of WD on copepods may have been mainly induced by the responses of Calanus sinicus and Paracyclopina nana. By inhibiting Stentor amethystinus and Vorticella lutea, pH significantly affected protozoa. In addition, Rotifera and copepods were affected by SAL mainly through the responses of Brachionus calyciflorus, Calanus sinicus, and Ectocyclops phaleratus. Importantly, fundamental alternations in the variation trends of zooplankton abundance and biomass along the salinity gradient were found when the salinity was approximately 4-5. By combining these results with the findings on phytoplankton responses to salinity in previous studies, it can be concluded that salinity may influence the river ecosystem by influencing zooplankton abundance and biomass rather than phytoplankton.

Clinical outcomes of an olive wire and external fixator versus a metallic screw in the treatment of inferior tibiofibular syndesmosis injuries in ankle fractures.

BACKGROUND: Metal screws are the most widely used in treating syndesmotic injuries, but failure and the rigidity of the screws can threaten the success of the treatment and increase the cost of care. We have provided an alternative with an olive wire and external fixator(OWEF) used for syndesmotic fixation. METHODS: A retrospective longitudinal follow-up study was conducted. From February 2011 to January 2018, 58 of 72 patients with ankle fractures and associated syndesmotic disruption were treated with either screw or OWEF fixation. The costs, complications, and clinical outcomes using Olerud-Molander score and Visual Analog score in screw and OWEF fixation group were compared. RESULTS: We found the severity of the injury, BMI of the patients and the different fixation methods were determinants of the complications and clinical outcomes. But if no malreduction of the syndesmosis was present, no difference in clinical result was detected. CONCLUSION: The OWEF method appeared to be at least equally functional and effective to screw fixation while maintaining possible lower complication rate. LEVELS OF CLINICAL EVIDENCE: Level 3.

Analysis on the stability of plankton in a food web with empirical organism body mass distribution.

The mechanism supporting the stability of complex food webs is an important, yet still controversial issue in ecology. Integrating the bioenergetic model with a natural plankton food web with empirical organism body mass distribution, we studied the effects of taxa diversity, nutrient enrichment simulation and connectance on the stability of plankton, and the underlying mechanisms. The behavior and functions of plankton with different body masses in the system were also explored. The results showed that genus richness promoted the temporal stability of community but reduced that of population. Meanwhile, the effects of taxon extinction on community biomass and temporal stability depended on the body masses of those lost taxa. Enrichment decreased phytoplankton and zooplankton community stability directly by increasing the temporal variability of biomass and indirectly by reducing taxa diversity. Enrichment preferentially caused phytoplankton taxa with the highest individual biomass to go extinct and the ones with smaller to increase in biomass. The effects, as well as the underlying mechanisms of connectance on phytoplankton and zooplankton stability were different. High connectance promoted the persistence and biomasses of both zooplankton and small-bodied phytoplankton but reduced those of larger-bodied phytoplankton. The results and methodology in this research will be helpful in understanding and analyzing the stability of plankton communities.

Effect of Insemination Methods on Pregnancy Outcomes of Day 6 Blastocyst Transfer in Frozen Cycles / 中山大学学报(医学科学版)

ObjectiveTo compare the effects of two different insemination methods， conventional in vitro fertilization （IVF） and intracytoplasmic sperm injection （ICSI）， on pregnancy outcomes in patients with frozen-thawed D6（day 6） blastocyst transfer. MethodsA retrospective cohort study was conducted to analyze the clinical data of patients with thawed D6 blastocyst transfer between January 2018 and April 2020 at the Fertility Center of the Third Hospital of Sun Yat-sen University， divided into conventional IVF group （446 cycles ） and ICSI fertilization group （200 cycles） according to the fertilization method. Patients were divided into those with a history of D5（day 5） blastocyst transfer and those without. The patients’ general characteristics， blastocyst quality， and pregnancy outcomes of the two groups were compared. ResultsBMI， years of infertility， and basal FSH were not statistically significant in the IVF and ICSI groups （P > 0.05）. Regardless of the history of D5 transfer， patients in the ICSI group were younger than those in the IVF group （P < 0.001）， the proportion of primary infertility was significantly higher in the ICSI group （P < 0.001）， and the number of oocytes obtained and the number of normally fertilized oocytes in the ICSI group were higher than those in the conventional IVF fertilization group （P < 0.001）. The proportion of stage V and Ⅵ blastocysts was significantly higher in the conventional IVF group than in the ICSI group （21.6 % vs. 3.14 %， P < 0.001）. High-quality blastocysts with an ICM score of A were significantly higher in the ICSI group than in the IVF group （23.8 % vs. 14.3 %， P = 0.01）. The HCG-positive and clinical pregnancy rates were significantly higher in the ICSI group than in the IVF group （65.5 % vs. 48.4 %， P < 0.001； 56 % vs. 41.3 %， P = 0.001）， and embryo implantation and live birth rates were also higher in the ICSI group than in the conventional IVF group （43.8 % vs. 30.9 %， P < 0.001； 43.0 % vs. 31.8 %， P = 0.006）. After correcting for age and number of oocytes obtained between the two groups， the clinical pregnancy rate was still significantly higher in the ICSI group than in the conventional IVF group （OR： 1.590， 95 % CI： 1.030， 2.455， P = 0.036）. Infant birth weight was lower in the ICSI group than in the IVF group （P = 0.016）， and the differences in preterm birth rate， sex ratio， and mode of delivery were not statistically significant between the two groups. ConclusionsClinical pregnancy and live birth rates after thawing and transfer of D6 blastocysts fertilized by ICSI are higher than those of D6 blastocysts fertilized by conventional IVF， which may be related to the different factors contributing to the slow development of blastocysts in patients who received different fertilization methods. The relatively good pregnancy outcome after the transfer of thawed D6 blastocysts fertilized by ICSI may compensate to some extent for the difference in pregnancy outcome due to the relatively slow blastocyst development and a relatively higher proportion of D6 blastocysts after ICSI fertilization in male infertility patients.