High production of optically pure (3R)-acetoin by a newly isolated marine strain of Bacillus subtilis CGMCC 13141.

Acetoin is one of the bio-based platform chemicals and its optically pure isomers are important potential intermediates and precursors in the synthesis of novel optically active materials. (3R)-acetoin could be synthesized via enzymatic catalysis, whole-cell catalysis and fermentation. In this study a marine strain of Bacillus subtilis was isolated to produce optically pure (3R)-acetoin with glucose as carbon source. The effects of nutrients on the formation of (3R)-acetoin and conversion of glucose to (3R)-acetoin were evaluated by Plackett-Burman design, and the fermentation medium was optimized by central composite design. The impact of oxygen supply on the production of (3R)-acetoin was studied at different aeration rates. Under the optimal conditions, 83.7 g/L (3R)-acetoin with an optical purity of 99.4% was achieved by fed-batch fermentation, and the conversion of glucose to (3R)-acetoin was 91.5% of the theoretical value. The results indicate the industrial potential of this strain for (3R)-acetoin production via fermentation.

Sugaring-out extraction of acetoin from fermentation broth by coupling with fermentation.

Acetoin is a natural flavor and an important bio-based chemical which could be separated from fermentation broth by solvent extraction, salting-out extraction or recovered in the form of derivatives. In this work, a novel method named as sugaring-out extraction coupled with fermentation was tried in the acetoin production by Bacillus subtilis DL01. The effects of six solvents on bacterial growth and the distribution of acetoin and glucose in different solvent-glucose systems were explored. The operation parameters such as standing time, glucose concentration, and volume ratio of ethyl acetate to fermentation broth were determined. In a system composed of fermentation broth, glucose (100%, m/v) and two-fold volume of ethyl acetate, nearly 100% glucose was distributed into bottom phase, and 61.2% acetoin into top phase without coloring matters and organic acids. The top phase was treated by vacuum distillation to remove solvent and purify acetoin, while the bottom phase was used as carbon source to produce acetoin in the next batch of fermentation.

Perceptions, Attitudes, Beliefs, and Practices Toward Traditional Chinese Medicine Therapies for Herpes Zoster: A Cross-Sectional Study of Healthcare Professionals.

Introduction: Traditional Chinese medicine (TCM) holds great potential in promoting healing and relieving pain for herpes zoster (HZ) treatments. Evidence showed that both healthcare professionals' (HCPs) belief and knowledge influence their attitudes, which result in their expression and direct behavior. However, little is known in this area regarding TCM treatments for HZ. This study aimed to understand the HCPs' perceptions, attitudes, beliefs, and practices toward TCM and its services for HZ. Methods: During July 2021 and October 2022, a cross-sectional study of HCPs querying demographics, perceptions, attitudes, beliefs, and practices toward TCM and TCM services for HZ was conducted. The frequency and percentage or mean and standard deviation were used to present categorical data and continuous data, respectively. A Chi-square analysis compared nurses' and doctors' views on TCM treatments for HZ. Results: Out of 306 eligible respondents, 66.0% used TCM content in clinical practice less than 40% of the time. Respondents reported that there were three main advantages of TCM for HZ, including better crusting and healing, fewer side effects, and mitigating complications. A total of 41.3% (81/196) of the respondents who had cared for/treated HZ patients applied TCM treatments. The three factors most associated with referrals/providing TCM to patients were postherpetic neuralgia, early erythema or papules, and acute pain. Compared to nurses, doctors showed more endorsement of the efficacy and cost-effectiveness of TCM treatments for HZ patients. Conclusion: The study found that most healthcare professionals in HZ had a favorable view of TCM, but lacked practical experience administering it to patients. Programs should be developed to provide evidence-based TCM treatments and encourage combining TCM with Western medicine for better patient care.

Pig blastocyst-like structure models from embryonic stem cells.

Pluripotent stem cells have the potential to generate embryo models that can recapitulate developmental processes in vitro. Large animals such as pigs may also benefit from stem-cell-based embryo models for improving breeding. Here, we report the generation of blastoids from porcine embryonic stem cells (pESCs). We first develop a culture medium 4FIXY to derive pESCs. We develop a 3D two-step differentiation strategy to generate porcine blastoids from the pESCs. The resulting blastoids exhibit similar morphology, size, cell lineage composition, and single-cell transcriptome characteristics to blastocysts. These porcine blastoids survive and expand for more than two weeks in vitro under two different culture conditions. Large animal blastoids such as those derived from pESCs may enable in vitro modeling of early embryogenesis and improve livestock species' breeding practices.

A tissue specific-infection mouse model of SARS-CoV-2.

Animal models play crucial roles in the rapid development of vaccines/drugs for the prevention and therapy of COVID-19, but current models have some deficits when studying the pathogenesis of SARS-CoV-2 on some special tissues or organs. Here, we generated a human ACE2 and SARS-CoV-2 NF/F knockin mouse line that constitutively expresses human ACE2 and specifically expresses SARS-CoV-2 N gene induced by Cre-recombinase. By crossing with Cre transgenic lines allowing for lung-specific and constitutive expression, we generated lung-specific (Sftpc-hACE2-NF/F) and constitutive SARS-CoV-2 N (EIIa-hACE2-NF/F) expressing mice. Upon intranasal infection with a SARS-CoV-2 GFP/ΔN strain which can only replicate in SARS-CoV-2 N expressed cells, we demonstrated that both the Sftpc-hACE2-NF/F and EIIa-hACE2-NF/F mice support viral replication. Consistent with our design, viral replication was limited to the lung tissues in Sftpc-hACE2-NF/F mice, while the EIIa-hACE2-NF/F mice developed infections in multiple tissues. Furthermore, our model supports different SARS-CoV-2 variants infection, and it can be successfully used to evaluate the effects of therapeutic monoclonal antibodies (Ab1F11) and antiviral drugs (Molnupiravir). Finally, to test the effect of SARS-CoV-2 infection on male reproduction, we generated Sertoli cell-specific SARS-CoV-2 N expressed mice by crossing with AMH-Cre transgenic line. We found that SARS-CoV-2 GFP/ΔN strain could infect Sertoli cells, led to spermatogenic defects due to the destruction of blood-testis barrier. Overall, combining with different tissue-specific Cre transgenic lines, the human ACE2 and SARS-CoV-2 NF/F line enables us to evaluate antivirals in vivo and study the pathogenesis of SARS-CoV-2 on some special tissues or organs.

The impact of physicians' knowledge on outpatient antibiotic use: Evidence from China's county hospitals.

We designed this study to explore how factors, especially knowledge, influence the use and prescriptions of antibiotics among physicians in China's county hospitals.A questionnaire was designed to evaluate the knowledge levels of physicians. The rates of antibiotic prescriptions were collected through on-the-spot investigations. The percentage of encounters with antibiotics prescribed and the percentage of encounters with antibiotics combination prescribed were used to measure antibiotics use. Univariate analysis and the generalized linear model were applied to analyze the knowledge levels among physicians as well as their antibiotic prescriptions.A total of 334 physicians in 60 county hospitals filled out the questionnaires, and 385,529 prescriptions were collected. The mean score of the questionnaire was a pass (62.8). The physicians in the eastern region of China demonstrated higher levels of knowledge than other regions (P = .08). Physicians with a higher score prescribed less antibiotics (P < .01) and less antibiotics combination (P = .07).The knowledge gap of Chinese physicians is evident and those with a higher degree of knowledge always prescribe fewer antibiotics. Targeted training and courses to educate physicians about the risks of over-prescription of antibiotics should be conducted to improve the practice of antibiotic prescriptions.