Efficiently manufacturing ectoine via metabolic engineering and protein engineering of L-2,4-diaminobutyrate transaminase.

Ectoine, so-called tetrahydropyrimidine, is an important osmotic adjustment solute and widely applied in cosmetics and protein protectant. Some attempts have been made to improve the ectoine productivity. However, the strains with both high ectoine production capacity and high glucose conversion were still absent so far. Aim to construct a strain for efficiently producing ectoine, ectoine synthetic gene cluster ectABC from Pseudomonas stutzeri was overexpressed in E. coli BL21 (DE3). The ection production was improved by 382 % (ectoine titer increased from 1.73 g/L to 8.33 g/L) after the rational design of rate-limiting enzyme L-2,4-diaminobutyrate transaminase EctBps (protein engineering) combined with the metabolic engineering that focused on the enrichment and conversion of precursors. The final strain YW20 was applied to overproduce ectoine in fed-batch fermentation and yield 68.9 g/L of ectoine with 0.88 g/L/h of space-time yield and the highest glucose conversion reported [34 % (g/g)]. From the fermentation broth, ectoine was purified with 99.7 % purity and 79.8 % yield. This study successfully provided an engineered strain as well as an efficient method for the industrial bio-synthesis and preparation of ectoine.

Validation of a Novel Mobile Application for Assessing Pediatric Tracheostomy Emergency Simulations.

Objective: Pediatric tracheostomy is associated with high morbidity and mortality, yet clinician knowledge and quality of tracheostomy care may vary widely. In situ simulation is effective at detecting and mitigating related latent safety threats, but evaluation via retrospective video review has disadvantages (eg, delayed analysis, and potential data loss). We evaluated whether a novel mobile application is accurate and reliable for assessment of in situ tracheostomy emergency simulations. Methods: A novel mobile application was developed for assessment of tracheostomy emergency in situ simulation team performance. After 1.25 hours of training, 6 raters scored 10 tracheostomy emergency simulation videos for the occurrence and timing of 12 critical steps. To assess accuracy, rater scores were compared to a reference standard to determine agreement for occurrence or absence of critical steps and a timestamp within ±5 seconds. Interrater reliability was determined through Cohen's and Fleiss' kappa and intraclass correlation coefficient. Results: Raters had 86.0% agreement with the reference standard when considering step occurrence and timing, and 92.8% agreement when considering only occurrence. The average timestamp difference from the reference standard was 1.3 ± 18.5 seconds. Overall interrater reliability was almost perfect for both step occurrence (Fleiss' kappa of 0.81) and timing of step (intraclass correlation coefficient of 0.99). Discussion: Using our novel mobile application, raters with minimal training accurately and reliably assessed videos of tracheostomy emergency simulations and identified areas for future refinement. Implications for Practice: With refinements, this innovative mobile application is an effective tool for real-time data capture of time-critical steps in in situ tracheostomy emergency simulations.

Practice Patterns in Asymmetric Sensorineural Hearing Loss: Survey Data.

OBJECTIVE: Although screening protocols for patients who present with asymmetric sensorineural hearing loss (ASNHL) exist, there are no clear guidelines to direct practitioners. In particular, various thresholds have been proposed for the degree of hearing loss that should prompt MRI studies, but the topic remains understudied. This project aims to compare protocols followed by practitioners to guide their imaging practices. STUDY DESIGN: Web-based survey. SETTING: Otolaryngology faculty at academic medical centers. METHODS: A list of 530 otolaryngologists (276 otology/neurotology specialists, 254 general otolaryngologists) was compiled. A survey consisting of three parts: demographics, general practice patterns, and simulated patient cases was distributed. RESULTS: A total of 468 surveys were successfully distributed, resulting in 88 (18.8%) responses. The majority of respondents (63.8%) self-reported their definition of ASNHL as ">30 dB hearing asymmetry at one frequency OR >20 dB hearing asymmetry at two continuous frequencies OR >10 dB hearing asymmetry at three contiguous frequencies." Overall, general otolaryngologists were more likely to observe asymmetric findings with serial audiogram alone, whereas otology/neurotology specialists were more likely to obtain imaging. CONCLUSION: There is significant variability between providers with regard to managing patients with ASNHL and evidence-based guidelines would be useful in guiding imaging practices. LEVEL OF EVIDENCE: N/A Laryngoscope, 2024.

Fe/Mn (oxyhydr)oxides reductive dissolution promoted by cyanobacterial algal bloom-derived dissolved organic matter caused sediment W release during an algal bloom in Taihu Lake.

Tungsten (W) can be toxic to aquatic organisms. However, the spatiotemporal characteristics and controlling factors of W mobility during harmful algal blooms (HABs) have rarely been investigated. In this study, simultaneous changes in soluble W, iron (Fe), manganese (Mn), and ultraviolet absorbance (UV254) in the sediment-water interface (SWI) were measured monthly using high-resolution peeper (HR-Peeper) devices. Laboratory experiments were conducted to verify the effects of environmental factors on W release. From May 2021 to October 2021, the concentration and flux of soluble W were higher than in other months. In addition, from May to October, DMAX (the depth at which the maximum concentration occurs on each profile) was 30-50 mm below the SWI, rather than the maximum depth. Principal component analysis (PCA) also divided the year into two periods, designated W-stable (December 2020, January, March, April and November 2021 with low soluble W concentration) and W-active periods (from May 2021 to October 2021 with high soluble W concentration). Laboratory experiments showed that both warming and anoxic conditions caused simultaneous release of soluble W, Fe(II), Mn, and dissolved organic matter (DOM), with strong correlations among soluble W, Fe(II), Mn. Partial least squares path modeling (PLS-PM) and random forest model showed that DOM directly affected W release or indirectly affected W release through promoting ferromanganese (oxyhydr)oxides reduction under warming and anaerobic conditions. The results of the field investigation showed that, in the W-stable period with low T, high DO, and an oxic SWI, the concentrations of soluble W, Fe, Mn, and DOM were low. The redundancy analysis (RDA) showed that these months were mainly affected by water DO. The significant and strong positive correlation among soluble W, Fe and Mn indicated that soluble W was probably scavenged by Fe/Mn (oxyhydr)oxides in the oxic water during the W-stable period. The W-active period corresponded to the cyanobacterial HABs (cyanoHABs) outbreak, with higher T, lower DO, and a more anoxic SWI. During this period, the concentrations of soluble W, Fe, Mn, and DOM were high and their correlations were stronger. RDA showed that these months were mainly affected by T, UV254, soluble Fe and Mn. These results indicated that reductive dissolution of Fe/Mn (oxyhydr)oxides driven by DOM generated in W-active period, especially cyanoHAB-derived DOM, mainly caused soluble W release. These results reveal the coupling relationship between cyanoHABs and W release and emphasize the need for prevention and control of heavy metal release in eutrophic lakes.

Dichorionic diamniotic twin pregnancy after preimplantation genetic testing and single blastocyst transfer.

BACKGROUND: In addition to the potential for multiple pregnancies, natural conception occurring in preimplantation genetic testing (PGT) increases undesired genetic risk. Some studies showed that a dichorionic diamniotic twin pregnancy after a single blastocyst transfer could be caused by embryo splitting or concurrent spontaneous conception. CASE: We describe a patient undergoing PGT who had a dichorionic diamniotic twin pregnancy after single blastocyst transfer in a natural cycle. In this case, we recommended to determine genetic status of the twins by prenatal diagnosis. The results showed that karyotype, chromosome copy number variation, and parental ACAT1 variation of the twins were all normal and similar. To investigate the origin of pregnancy, we used the genotype data of single-nucleotide polymorphisms typical of genome-wide association studies. Dizygotic twins were inferred by robust estimation of kinship coefficients, which confirmed the occurrence of a spontaneous conception. CONCLUSIONS: This case strengthens the importance of genetic counseling to inform couples with reproductive genetic risk, such as those who undergo PGT, that intercourse should be avoided, especially in natural transfer cycles. Moreover, prenatal diagnosis remains essential and is strongly recommended to avoid genetic risks.

Development of whole cell biocatalytic system for asymmetric synthesis of esomeprazole with enhancing coenzyme biosynthesis pathway.

Esomeprazole is the most popular proton pump inhibitor for treating gastroesophageal reflux disease. Previously, a phenylacetone monooxygenase mutant LnPAMOmu15 (LM15) was obtained by protein engineering for asymmetric synthesis of esomeprazole using pyrmetazole as substrate. To scale up the whole cell asymmetric synthesis of esomeprazole and reduce the cost, in this work, an Escherichia coli whole-cell catalyst harboring LM15 and formate dehydrogenase from Burkholderia stabilis 15516 (BstFDH) were constructed through optimized gene assembly patterns. CRISPR/Cas9 mediated insertion of Ptrc promoter in genome was done to enhance the expression of key genes to increase the cellular NADP supply in the whole cell catalyst, by which the amount of externally added NADP+ for the asymmetric synthesis of esomeprazole decreased to 0.05 mM from 0.3 mM for reducing the cost. After the optimization of reaction conditions in the reactor, the scalable synthesis of esomeprazole was performed using the efficient LM15-BstFDH whole-cell as catalyst, which showed the highest reported space-time yield of 3.28 g/L/h with 50 mM of pyrmetazole loading. Isolation procedure was conducted to obtain esomeprazole sodium of 99.55 % purity and > 99.9 % ee with 90.1 % isolation yield. This work provides the basis for production of enantio-pure esomeprazole via cost-effective whole cell biocatalysis.

Digital therapeutics-based lifestyle intervention for gestational diabetes mellitus prevention of high-risk pregnant women: a study protocol for a non-randomised controlled trial.

INTRODUCTION: Digital therapeutics have been approved as a treatment aid for various medical conditions and are increasingly prevalent. Despite numerous studies on the potential of digital therapeutic interventions in preventing gestational diabetes mellitus (GDM), there is a critical need for more high-quality, large-scale studies to validate their effectiveness. This need arises from the inconsistencies in results and variations in the quality of previous research. METHODS AND ANALYSIS: We propose a non-randomised controlled trial involving 800 high-risk pregnant women in 6 maternity and child health hospitals in Fujian, China. This study aims to investigate the role and effectiveness of digital therapeutics-based lifestyle intervention in managing the health of pregnant women at high risk for GDM. The study will compare the differences in GDM prevalence, pregnancy weight management and other pregnancy-related health outcomes between pregnant women who received digital therapeutics-based lifestyle intervention and those in the control group. The intervention includes dietary guidance, a personalised physical activity programme and lifestyle improvement strategies delivered through a smartphone app. Primary outcomes include the incidence of GDM at 24-28 weeks gestation and gestational weight gain (GWG). Secondary outcomes comprise improvements in individual lifestyle and risk factors, nutritional issues, implementation outcomes and other pregnancy-related outcomes. ETHICS AND DISSEMINATION SECTION: The trial was approved by the Ethics Committee of Fujian Maternity and Child Health Hospital (approval number: 2023KY046), Jianyang Maternity and Child Health Hospital (approval number: A202401), Fuqing Maternity and Child Health Hospital (approval number: FY2024003), Changting Maternity and Child Health Hospital (approval number: 202401), Datian Maternity and Child Health Hospital (approval number: dtfy202401) and Quanzhou Maternity and Child Health Hospital (approval number: 2024(50)). We will disseminate our findings by publishing articles in leading peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCTR2300071496.

Multienzymatic Cascade for Synthesis of Hydroxytyrosol via Two-Stage Biocatalysis.

Hydroxytyrosol, a naturally occurring compound with antioxidant and antiviral activity, is widely applied in the cosmetic, food, and nutraceutical industries. The development of a biocatalytic approach for producing hydroxytyrosol from simple and readily accessible substrates remains a challenge. Here, we designed and implemented an effective biocatalytic cascade to obtain hydroxytyrosol from 3,4-dihydroxybenzaldehyde and l-threonine via a four-step enzymatic cascade composed of seven enzymes. To prevent cross-reactions and protein expression burden caused by multiple enzymes expressed in a single cell, the designed enzymatic cascade was divided into two modules and catalyzed in a stepwise manner. The first module (FM) assisted the assembly of 3,4-dihydroxybenzaldehyde and l-threonine into (2S,3R)-2-amino-3-(3,4-dihydroxyphenyl)-3-hydroxypropanoic acid, and the second module (SM) entailed converting (2S,3R)-2-amino-3-(3,4-dihydroxyphenyl)-3-hydroxypropanoic acid into hydroxytyrosol. Each module was cloned into Escherichia coli BL21 (DE3) and engineered in parallel by fine-tuning enzyme expression, resulting in two engineered whole-cell catalyst modules, BL21(FM01) and BL21(SM13), capable of converting 30 mM 3,4-dihydroxybenzaldehyde to 28.7 mM hydroxytyrosol with a high space-time yield (0.88 g/L/h). To summarize, the current study proposes a simple and effective approach for biosynthesizing hydroxytyrosol from low-cost substrates and thus has great potential for industrial applications.

Single-cell enzymatic cascade synthesis of testolactone enabled by engineering of polycyclic ketone monooxygenase and multi-gene expression fine-tuning.

The synthesis of steroids is challenging through multistep steroidal core modifications with high site-selectivity and productivity. In this work, a novel enzymatic cascade system was constructed for synthesis of testolactone by specific C17 lactonization/Δ1-dehydrogenation from inexpensive androstenedione using an engineered polycyclic ketone monooxygenase (PockeMO) and an appropriate 3-ketosteroid-Δ1-dehydrogenase (ReKstD). The focused saturation mutagenesis in the substrate binding pocket was implemented for evolution of PockeMO to eliminate the bottleneck effect. A best mutant MU3 (I225L/L226V/L532Y) was obtained with 20-fold higher specific activity compared to PockeMO. The catalytic efficiency (kcat/Km) of MU3 was 171-fold higher and the substrate scope shifted to polycyclic ketones. Molecular dynamic simulations suggested that the activity was improved by stabilization of the pre-lactonization state and generation of productive orientation of 4-AD mediated by distal L532Y mutation. Based on that, the three genes, MU3, ReKstD and a ketoreductase for NADPH regeneration, were rationally integrated in one cell via expression fine-tuning to form the efficient single cell catalyst E. coli S9. The single whole-cell biocatalytic process was scaled up and could generate 9.0 g/L testolactone with the high space time yield of 1 g/L/h without steroidal by-product, indicating the potential for site-specific and one-pot synthesis of steroid.

[Construction and external validation of a risk prediction model for unplanned interruption during continuous renal replacement therapy].

OBJECTIVE: To identify the independent factors of unplanned interruption during continuous renal replacement therapy (CRRT) and construct a risk prediction model, and to verify the clinical application effectiveness of the model. METHODS: A retrospective study was conducted on critically ill adult patients who received CRRT treatment in the intensive care unit (ICU) of Zhejiang Hospital from January 2021 to August 2022 for model construction. According to whether unplanned weaning occurred, the patients were divided into two groups. The potential influencing factors of unplanned CRRT weaning in the two groups were compared. The independent influencing factors of unplanned CRRT weaning were screened by binary Logistic regression and a risk prediction model was constructed. The goodness of fit of the model was verified by a Hosmer-Lemeshow test and its predictive validity was evaluated by receiver operator characteristic curve (ROC curve). Then embed the risk prediction model into the hospital's ICU multifunctional electronic medical record system for severe illness, critically ill patients with CRRT admitted to the ICU of Zhejiang Hospital from November 2022 to October 2023 were prospectively analyzed to verify the model's clinical application effect. RESULTS: (1) Model construction and internal validation: a total of 331 critically ill patients with CRRT were included to be retrospectively analyzed. Among them, there were 238 patients in planned interruption group and 93 patients in unplanned interruption group. Compared with the planned interruption group, the unplanned interruption group was shown as a lower proportion of males (80.6% vs. 91.6%) and a higher proportion of chronic diseases (60.2% vs. 41.6%), poor blood purification catheter function (31.2% vs. 6.3%), as a higher platelet count (PLT) before CRRT initiation [×109/L: 137 (101, 187) vs. 109 (74, 160)], lower level of blood flow rate [mL/min: 120 (120, 150) vs. 150 (140, 180)], higher proportion of using pre-dilution (37.6% vs. 23.5%), higher filtration fraction [23.0% (17.5%, 32.9%) vs. 19.1% (15.7%, 22.6%)], and frequency of blood pump stops [times: 19 (14, 21) vs. 9 (6, 13)], the differences of the above 8 factors between the two groups were statistically significant (all P < 0.05). Binary Logistic regression analysis showed that chronic diseases [odds ratio (OR) = 3.063, 95% confidence interval (95%CI) was 1.200-7.819], blood purification catheter function (OR = 4.429, 95%CI was 1.270-15.451), blood flow rate (OR = 0.928, 95%CI was 0.900-0.957), and frequency of blood pump stops (OR = 1.339, 95%CI was 1.231-1.457) were the independent factors for the unplanned interruption of CRRT (all P < 0.05). These 4 factors were used to construct a risk prediction model, and ROC curve analysis showed that the area under the curve (AUC) predicted by the model was 0.952 (95%CI was 0.930-0.973, P = 0.003 0), with a sensitivity of 88.2%, a specificity of 89.9%, and a maximum value of 1.781 for the Youden index. (2) External validation: prospective inclusion of 110 patients, including 63 planned interruption group and 47 unplanned interruption group. ROC curve analysis showed that the AUC of the risk prediction model was 0.919 (95%CI was 0.870-0.969, P = 0.004 3), with a sensitivity of 91.5%, a specificity of 79.4%, and a maximum value of the Youden index of 1.709. CONCLUSIONS: The risk prediction model for unplanned interruption during CRRT has a high predictive efficiency, allowing for rapid and real-time identification of the high risk patients, thus providing references for preventative nursing.

Physical Activity, Cardiovascular Status, Mortality, and Prediabetes in Hispanic and Non-Hispanic Adults.

Importance: Data are limited on the association of physical activity (PA) with incident cardiovascular disease (CVD) and mortality in prediabetes, especially in racial and ethnic minority groups, including Hispanic and Latino populations. Objective: To determine the association of PA with incident CVD and mortality by prediabetes status among Hispanic or Latino and non-Hispanic adults. Design, Setting, and Participants: This cohort study included data from 2 cohorts of adults with prediabetes or normoglycemia who were free of CVD at baseline visit: the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) from baseline examination through 2017, with median (IQR) follow-up of 7.8 (7.2-8.5) years, and the Framingham Heart Study (FHS) with non-Hispanic participants from index examination through 2019, with median (IQR) follow-up of 9.6 (8.1-10.7) years. Analyses were conducted between September 1, 2022, and January 10, 2024. Exposure: The primary exposure was baseline accelerometry-measured moderate to vigorous PA, insufficient vs sufficient to meet 2018 Physical Activity Guidelines for Americans (PAG) in both cohorts; additional accelerometer-measured exposures in HCHS/SOL were steps per day, sedentary behavior, and counts per min. Main Outcomes and Measures: The outcome was a composite of incident CVD or all-cause mortality, whichever came first. Results: This cohort study included 13 223 participants: from HCHS/SOL, there were 9456 adults (all self-identified Hispanic or Latino ethnicity; survey-adjusted mean [SD] age, 38.3 [13.9] years, unweighted counts 5673 (60.0%) female; 4882 [51.6%] with normoglycemia; 4574 [48.4%] with prediabetes), and from FHS there were 3767 adults (3623 [96.2%] non-Hispanic and 140 [3.7%] Hispanic or Latino ethnicity, with 4 [0.1%] participants missing ethnicity; mean [SD] age, 54.2 [13.6] years; 2128 (56.5%) female; 2739 [72.7%] with normoglycemia; 1028 [27.3%] with prediabetes). Not meeting PAG was associated with higher risk of the composite outcome among participants with normoglycemia (vs PAG met; hazard ratio [HR], 1.85 [95% CI, 1.12-3.06]), but not among participants with prediabetes (HR, 1.07 [95% CI, 0.72-1.58]). For HCHS/SOL, no statistically significant association was found between the composite outcome and other PA metrics, although estimated HRs tended to be higher for lower activity in the normoglycemia group but not for the prediabetes group (eg, for steps less than vs at least 7000 per day, the HR was 1.58 [95% CI, 0.85-2.93] for normoglycemia vs 1.08 [95% CI 0.67-1.74] for prediabetes). While there was also no association in HCHS/SOL between the composite outcome and sedentary behavior, results were similar in the prediabetes group (HR per 30 minutes per day of sedentary behavior, 1.05 [95% CI 0.99-1.12]) and in the normoglycemia group (HR, 1.07 [95% CI 0.98-1.16]). Conclusions and Relevance: In this cohort study of US Hispanic or Latino and non-Hispanic adults, lower moderate to vigorous PA levels were associated with CVD or mortality among participants with normoglycemia but not participants with prediabetes. Adults with prediabetes may benefit from reducing sedentary behavior and improving multiple lifestyle factors beyond improving moderate to vigorous PA alone.

Preventing Infection in Pediatric Patients Receiving Chemotherapy: A Survey of Provider Recommendations.

PURPOSE: Sepsis is the leading cause of mortality in patients with childhood cancer receiving cytotoxic chemotherapy. Pediatric hematology/oncology and transplant (PHOT) providers must counsel their patients on the safety of public activities and weigh the risk of infection exposure with the social and developmental benefits of in-person school and social outings. We hypothesize that there is significant variability in recommendations given by PHOT providers. METHODS: An electronic anonymous survey was developed and piloted by a group of PHOT providers to assess current methods for educating patients and families on limiting infectious exposures. Five clinical vignettes were created by the study team to explore how providers balance the competing priorities of safety and health-related quality of life (HRQoL). The electronic survey was institutional review board-approved and disseminated via email to all PHOT providers affiliated with the Children's Oncology Group across the United States. RESULTS: In total, 545 clinicians completed the survey. Most respondents were attending physicians (393, 72%), followed by fellows (61, 11%), advanced practice providers (APPs; 38, 7%), and nurses (37, 7%). On average, nurses and fellows made more conservative recommendations for avoiding infectious exposures compared with the recommendations from attending physicians and APPs (P < .0001). On average, providers with more years of clinical experience expressed less cautious recommendations, whereas those with less years of experience provided more cautious recommendations for avoiding infectious exposures (P = .0072). CONCLUSION: This survey demonstrates the importance of collaboration between all members of the care team in defining priorities for balancing safety risk and HRQoL to provide consistent messaging to patients. The variations in survey responses highlight the need for universal guidelines to standardize physician recommendations for limiting infectious exposures in pediatric patients on chemotherapy.

[Preparation technology comparison and performance evaluation of different protein A affinity chromatographic materials].

Protein A affinity chromatographic materials are widely used in clinical medicine and biomedicine because of their specific interactions with immunoglobulin G (IgG). Both the characteristics of the matrix, such as its structure and morphology, and the surface modification method contribute to the affinity properties of the packing materials. The specific, orderly, and oriented immobilization of protein A can reduce its steric hindrance with the matrix and preserve its bioactive sites. In this study, four types of affinity chromatographic materials were obtained using agarose and polyglycidyl methacrylate (PGMA) spheres as substrates, and multifunctional epoxy and maleimide groups were used to fix protein A. The effects of the ethylenediamine concentration, reaction pH, buffer concentration, and other conditions on the coupling efficiency of protein A and adsorption performance of IgG were evaluated. Multifunctional epoxy materials were prepared by converting part of the epoxy groups of the agarose and PGMA matrices into amino groups using 0.2 and 1.6 mol/L ethylenediamine, respectively. Protein A was coupled to the multifunctional epoxy materials using 5 mmol/L borate buffer (pH 8) as the reaction solution. When protein A was immobilized on the substrates by maleimide groups, the agarose and PGMA substrates were activated with 25% (v/v) ethylenediamine for 16 h to convert all epoxy groups into amino groups. The maleimide materials were then converted into amino-modified materials by adding 3 mg/mL 3-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS) dissolved in dimethyl sulfoxide (DMSO) and then suspended in 5 mmol/L borate buffer (pH 8). The maleimide groups reacted specifically with the C-terminal of the sulfhydryl group of recombinant protein A to achieve highly selective fixation on both the agarose and PGMA substrates. The adsorption performance of the affinity materials for IgG was improved by optimizing the bonding conditions of protein A, such as the matrix type, matrix particle size, and protein A content, and the adsorption properties of each affinity material for IgG were determined. The column pressure of the protein A affinity materials prepared using agarose or PGMA as the matrix via the maleimide method was subsequently evaluated at different flow rates. The affinity materials prepared with PGMA as the matrix exhibited superior mechanical strength compared with the materials prepared with agarose. Moreover, an excellent linear relationship between the flow rate and column pressure of 80 mL/min was observed for this affinity material. Subsequently, the effect of the particle size of the PGMA matrix on the binding capacity of IgG was investigated. Under the same protein A content, the dynamic binding capacity of the affinity materials on the PGMA matrix was higher when the particle size was 44-88 µm than when other particle sizes were used. The properties of the affinity materials prepared using the multifunctional epoxy and maleimide-modified materials were compared by synthesizing affinity materials with different protein A coupling amounts of 1, 2, 4, 6, 8, and 10 mg/mL. The dynamic and static binding capacities of each material for bovine IgG were then determined. The prepared affinity material was packed into a chromatographic column to purify IgG from bovine colostrum. Although all materials showed specific adsorption selectivity for IgG, the affinity material prepared by immobilizing protein A on the PGMA matrix with maleimide showed significantly better performance and achieved a higher dynamic binding capacity at a lower protein grafting amount. When the protein grafting amount was 15.71 mg/mL, the dynamic binding capacity of bovine IgG was 32.23 mg/mL, and the dynamic binding capacity of human IgG reached 54.41 mg/mL. After 160 cycles of alkali treatment, the dynamic binding capacity of the material reached 94.6% of the initial value, indicating its good stability. The developed method is appropriate for the production of protein A affinity chromatographic materials and shows great potential in the fields of protein immobilization and immunoadsorption material synthesis.

A memory access gate controlled by dynamic contexts.

Temporary difficulties in accessing the contents of memories are a common experience in everyday life, for example, when we try to recognize a known person in an unusual context. In addition, recent experiments seem to indicate that retrograde amnesia in the early stages of Alzheimer's disease is due to disorders in accessing memories that were installed normally. These facts suggest the existence of an intermediate step between the stimulus arrival and the associative recognition. In this work, a multimodular neurocomputational model is presented postulating the existence of a neural gate that controls the access of the stimulus with its context to the consolidated memory. If recognition is not achieved, a random search is initiated in a contextual network aroused by the initial context. The search continues until the appropriate context that allows for recognition is found or until the process is turned off because the initial stimulus is no longer maintained in the working memory. The model is based on vector patterns of neural activity and context-dependent matrix memories. Simple Markov chain simulations are presented to exemplify possible search scenarios in the contextual network. Finally, we discuss some of the characteristics of the model and the phenomenon under study.

[Bushen Culuan Formula in treatment of infertility caused by polycystic ovary syndrome].

This study aims to observe the efficacy and safety of Bushen Culuan Formula in the treatment of infertility caused by polycystic ovary syndrome(PCOS) and to explore the mechanism using metabolomics. Ninety-four patients with infertility caused by PCOS with the syndrome of kidney deficiency and blood stasis were selected and assigned into treatment and control groups(n=47). The basal body temperature(BBT) was measured, and B-ultrasonography was employed to monitor follicles, ovarian volume, endometrium, ovulation, and pregnancy. The serum levels of sex hormones including follicle-stimulating hormone(FSH), luteinizing hormone(LH), prolactin(PRL), estradiol(E_2), progestin(P), testosterone(T), free testosterone(FT), androstenedione(A2), inhibin B(INHB), and anti-Müllerian hormone(AMH) were measured. The coagulation function, traditional Chinese medicine(TCM) symptom scores, blood and urine routine, liver and kidney functions and other safety indicators were determined. Metabolomics was employed to comparatively analyze the serum metabolites of 26 patients(13 patients in each group) in the clinical study. The results showed that the total response rate and pregnancy rate of the treatment group were higher than those of the control group(P<0.001), suggesting that Bushen Culuan Formula regulated the sex hormones and ovarian function. Specifically, it reduced the levels of LH, T, FT, A2, and INHB(P<0.05 or P<0.01) and the LH/FSH ratio(P<0.05), elevated the level of P(P<0.05), promoted ovulation, increased endothelial thickness, and lowered TCM symptom scores without causing adverse reactions. A total of 24 differential metabolites were screened by metabolomics, and there were correlations between sex hormones and differential metabolites in the PCOS-induced infertility patients with kidney deficiency and blood stasis. In conclusion, Bushen Culuan Formula may regulate hormone levels through lipid and amino acid metabolism.

The RIPK1 death domain restrains ZBP1- and TRIF-mediated cell death and inflammation.

RIPK1 is a multi-functional kinase that regulates cell death and inflammation and has been implicated in the pathogenesis of inflammatory diseases. RIPK1 acts in a kinase-dependent and kinase-independent manner to promote or suppress apoptosis and necroptosis, but the underlying mechanisms remain poorly understood. Here, we show that a mutation (R588E) disrupting the RIPK1 death domain (DD) caused perinatal lethality induced by ZBP1-mediated necroptosis. Additionally, these mice developed postnatal inflammatory pathology, which was mediated by necroptosis-independent TNFR1, TRADD, and TRIF signaling, partially requiring RIPK3. Our biochemical mechanistic studies revealed that ZBP1- and TRIF-mediated activation of RIPK3 required RIPK1 kinase activity in wild-type cells but not in Ripk1R588E/R588E cells, suggesting that DD-dependent oligomerization of RIPK1 and its interaction with FADD determine the mechanisms of RIPK3 activation by ZBP1 and TRIF. Collectively, these findings revealed a critical physiological role of DD-dependent RIPK1 signaling that is important for the regulation of tissue homeostasis and inflammation.

Comprehensive genome-wide analysis of wheat xylanase inhibitor protein (XIP) genes: unveiling their role in Fusarium head blight resistance and plant immune mechanisms.

In this comprehensive genome-wide study, we identified and classified 83 Xylanase Inhibitor Protein (XIP) genes in wheat, grouped into five distinct categories, to enhance understanding of wheat's resistance to Fusarium head blight (FHB), a significant fungal threat to global wheat production. Our analysis reveals the unique distribution of XIP genes across wheat chromosomes, particularly at terminal regions, suggesting their role in the evolutionary expansion of the gene family. Several XIP genes lack signal peptides, indicating potential alternative secretion pathways that could be pivotal in plant defense against FHB. The study also uncovers the sequence homology between XIPs and chitinases, hinting at a functional diversification within the XIP gene family. Additionally, the research explores the association of XIP genes with plant immune mechanisms, particularly their linkage with plant hormone signaling pathways like abscisic acid and jasmonic acid. XIP-7A3, in particular, demonstrates a significant increase in expression upon FHB infection, highlighting its potential as a key candidate gene for enhancing wheat's resistance to this disease. This research not only enriches our understanding of the XIP gene family in wheat but also provides a foundation for future investigations into their role in developing FHB-resistant wheat cultivars. The findings offer significant implications for wheat genomics and breeding, contributing to the development of more resilient crops against fungal diseases.

In situ fabrication of covalent organic frameworks on solid-phase microextraction probes coupled with electrospray ionization mass spectrometry for enrichment and determination of androgens in biosamples.

Solid-phase microextraction (SPME) coupled with electrospray ionization mass spectrometry (ESI-MS) was developed for rapid and sensitive determination of endogenous androgens. The SPME probe is coated with covalent organic frameworks (COFs) synthesized by reacting 1,3,5-tri(4-aminophenyl)benzene (TPB) with 2,5-dioctyloxybenzaldehyde (C8PDA). This COFs-SPME probe offers several advantages, including enhanced extraction efficiency and stability. The analytical method exhibited wide linearity (0.1-100.0 µg L-1), low limits of detection (0.03-0.07 µg L-1), high enrichment factors (37-154), and satisfactory relative standard deviations (RSDs) for both within one probe (4.0-14.8%) and between different probes (3.4-12.7%). These remarkable performance characteristics highlight the reliability and precision of the COFs-SPME-ESI-MS method. The developed method was successfully applied to detect five kinds of endogenous androgens in female serum samples, indicating that the developed analytical method has great potential for application in preliminary clinical diagnosis.

Impact of Alcian blue and periodic acid Schiff expression on the prognosis of gastric signet ring cell carcinoma.

BACKGROUND: The Alcian blue (AB) and periodic acid Schiff (PAS) stains are representative mucus markers in gastric signet ring cell carcinoma (SRCC). They are low-cost special staining methods used to detect acidic mucus and neutral mucus, respectively. However, the clinical importance of the special combined AB and PAS stain is unclear. AIM: To investigate AB expression, PAS expression and the AB-to-PAS (A/P) ratio in gastric SRCC patients and to assess patient prognosis. METHODS: Paraffin-embedded sections from 83 patients with gastric SRCC were stained with AB and PAS, and signet ring cell positivity was assessed quantitatively. Immunohistochemical staining for Ki67, protein 53 (P53) and human epidermal growth factor receptor 2 (HER2) was performed simultaneously. The cancer-specific survival (CSS) rate was estimated via Kaplan-Meier analysis. Cox proportional hazards models were used for univariate and multivariate survival analyses. RESULTS: Kaplan-Meier survival analysis revealed that the 3-year CSS rate was significantly greater in the high-PAS-expression subgroup than in the low-PAS-expression subgroup (P < 0.001). The 3-year CSS rate in the A/P ≤ 0.5 group was significantly greater than that in the A/P > 0.5 group (P = 0.042). Univariate Cox regression analysis revealed that the factors affecting prognosis included tumor diameter, lymph node metastasis, vessel carcinoma embolus, tumor stage, the A/P ratio and the expression of Ki67, P53 and the PAS. Cox multivariate regression analysis confirmed that low PAS expression [hazard ratio (HR) = 3.809, 95% confidence interval (CI): 1.563-9.283, P = 0.003] and large tumor diameter (HR = 2.761, 95%CI: 1.086-7.020, P = 0.033) were independent risk factors for poor prognosis. CONCLUSION: A/P > 0.5 is potentially a risk factor for prognosis, and low PAS expression is an independent risk factor in the prognosis of gastric SRCC. PAS expression and the A/P ratio could help in predicting the clinical prognosis of patients with SRCC.

Real-world application of nirmatrelvir/ritonavir in hospitalized COVID-19 patients with onset of symptoms beyond 5 days: a comparative study.

PURPOSE: Physicians may administer Nirmatrelvir-ritonavir to patients who have been symptomatic for more than 5 days. There is currently no clear evidence to support this approach. METHODS: A real-world study was conducted to investigate the potential relationship between the administration of Nirmatrelvir-ritonavir and the rates of intubation or in-hospital mortality among COVID-19 patients who experienced symptoms for more than 5 days. The end point was a composite event of intubation or in-hospital mortality. The outcomes between those patients who received Nirmatrelvir-ritonavir and those who did not were compared. RESULTS: A total of 847 patients were included in the analysis. Among them, 312 patients (36.84%) received Nirmatrelvir-ritonavir. Within the entire population, 86 patients (10.15%) experienced intubation or in-hospital mortality. The main analysis indicated that there was a significant association between the application of Nirmatrelvir-ritonavir and intubation or in-hospital mortality, with an odds ratio of 0.50 (95% confidence interval, 0.28 to 0.87; P = 0.0153) using inverse probability of treatment weighting. The finding was consistent with multiple sensitivity analyses. CONCLUSIONS: The application of Nirmatrelvir-ritonavir was associated with a significantly reduced risk of intubation or death in hospitalized COVID-19 patients who experienced symptoms for more than 5 days as compared to those who did not receive the treatment.