Elucidating nanostructural organization and photonic properties of butterfly wing scales using hyperspectral microscopy.

Biophotonic nanostructures in butterfly wing scales remain fascinating examples of biological functional materials, with intriguing open questions with regard to formation and evolutionary function. One particularly interesting butterfly species, Erora opisena (Lycaenidae: Theclinae), develops wing scales that contain three-dimensional photonic crystals that closely resemble a single gyroid geometry. Unlike most other gyroid-forming butterflies, E. opisena develops discrete gyroid crystallites with a pronounced size gradient hinting at a developmental sequence frozen in time. Here, we present a novel application of a hyperspectral (wavelength-resolved) microscopy technique to investigate the ultrastructural organization of these gyroid crystallites in dry, adult wing scales. We show that reflectance corresponds to crystallite size, where larger crystallites reflect green wavelengths more intensely; this relationship could be used to infer size from the optical signal. We further successfully resolve the red-shifted reflectance signal from wing scales immersed in refractive index liquids with varying refractive index, including values similar to water or cytosol. Such photonic crystals with lower refractive index contrast may be similar to the hypothesized nanostructural forms in the developing butterfly scales. The ability to resolve these fainter signals hints at the potential of this facile light microscopy method for in vivo analysis of nanostructure formation in developing butterflies.

Is there a duration-characteristic relationship for trypsin exposure on tendon? A study on anterior cruciate ligament reconstruction in a rabbit model.

Background: Decellularized allograft tendons are highly regarded for their accessibility and the reduced risk of immune rejection, making them a promising choice for grafting due to their favorable characteristics. However, effectively integrating reconstructed tendons with host bone remains a significant clinical challenge. Purpose: This study aims to investigate the relationship between the duration of tendon exposure to trypsin and its impact on tendon biomechanical properties and healing capacity. Methods: Morphological assessments and biochemical quantifications were conducted. Allograft tendons underwent heterotopic transplantation into the anterior cruciate ligament (ACL) in a rabbit model, with specimens harvested 6 weeks post-surgery for a comparative analysis of cell adhesion strength and mechanical performance. Duration-response curves were constructed using maximum stress and cell adhesion quantity as primary indicators. Results: The trypsin treatment enhanced cell adhesion on the tendon surface. Adhesion rates in the control group vs. the experimental groups were as follows: 3.10 ± 0.56% vs. 4.59 ± 1.51%, 5.36 ± 1.24%, 6.12 ± 1.98%, and 8.27 ± 2.34% (F = 6.755, p = 0.001). However, increasing treatment duration led to a decline in mechanical properties, with the ultimate load (N) in the control vs. experimental groups reported as 103.30 ± 10.51 vs. 99.59 ± 4.37, 93.15 ± 12.38, 90.42 ± 7.87, and 82.68 ± 6.89, F = 4.125 (p = 0.013). Conclusion: The findings reveal an increasing trend in adhesion effectiveness with prolonged exposure duration, while mechanical strength declines. The selection of the optimal processing duration should involve careful consideration of the benefits derived from both outcomes.

Electroporation Delivery of Cas9 sgRNA Ribonucleoprotein-Mediated Genome Editing in Sheep IVF Zygotes.

The utilization of electroporation for delivering CRISPR/Cas9 system components has enabled efficient gene editing in mammalian zygotes, facilitating the development of genome-edited animals. In this study, our research focused on targeting the ACTG1 and MSTN genes in sheep, revealing a threshold phenomenon in electroporation with a voltage tolerance in sheep in vitro fertilization (IVF) zygotes. Various poring voltages near 40 V and pulse durations were examined for electroporating sheep zygotes. The study concluded that stronger electric fields required shorter pulse durations to achieve the optimal conditions for high gene mutation rates and reasonable blastocyst development. This investigation also assessed the quality of Cas9/sgRNA ribonucleoprotein complexes (Cas9 RNPs) and their influence on genome editing efficiency in sheep early embryos. It was highlighted that pre-complexation of Cas9 proteins with single-guide RNA (sgRNA) before electroporation was essential for achieving a high mutation rate. The use of suitable electroporation parameters for sheep IVF zygotes led to significantly high mutation rates and heterozygote ratios. By delivering Cas9 RNPs and single-stranded oligodeoxynucleotides (ssODNs) to zygotes through electroporation, targeting the MSTN (Myostatin) gene, a knock-in efficiency of 26% was achieved. The successful generation of MSTN-modified lambs was demonstrated by delivering Cas9 RNPs into IVF zygotes via electroporation.

Effect of the national integrated demonstration area for the prevention and control of noncommunicable diseases programme on behavioural risk factors in China: a synthetic difference-in-differences study.

Background: The government-led community-based Chinese National Integrated Demonstration Areas for the Prevention and Control of Noncommunicable Diseases programme was launched in 2011, but no rigorous impact evaluation has been conducted to date. We aimed to evaluate the causal effects of this programme on behavioural risk factors. Methods: We used data from the latest five waves of the China Chronic Disease and Risk Factor Surveillance. The primary outcome is a behavioural risk score combining current smoking, passive smoking, drinking in last month, regular exercise, body mass index, and waist circumference. We applied the synthetic difference-in-differences method and constructed synthetic controls from the non-demonstration areas with the outcome. The average treatment effects on the treated were estimated for overall effect and by short- (1-2), medium- (3-4), and long-term (6-7 years) effects. Findings: We identified 26 demonstration areas (N = 72,193) and 100 non-demonstration areas (N = 275,397). Participants in the demonstration areas had higher education and income levels and different pre-implementation trends than non-demonstration areas. Using synthetic controls instead of non-demonstration areas reduced these pre-implementation differences. Compared to the synthetic controls, declines were observed in current smoking (-1.78% [-4.51%, 0.96%]), passive smoking (-8.09% [-14.27%, -1.90%]), and drinking in last month (-4.04% [-8.75%, 0.67%]) but not in the other factors. Behavioural risk score declined by 1.05 short-term (95% CI: -1.84, -0.26), 1.15 medium-term (95% CI: -2.08, -0.22), 2.82 long-term (95% CI: -4.79, -0.85), and 1.54 overall (95% CI: -2.51, -0.56). Interpretation: The programme improved behavioural risk scores, primarily through reductions in the prevalence of smoking and drinking, and the effect was long-lasting. Our findings provided empirical evidence for utilizing an integrated prevention and control strategy to fight against NCD in China and other countries facing similar challenges. Funding: The China National Key Research and Development Program (2018YFC1315304 and 2017YFC1310902); National Natural Science Foundation of China (81872721).

Electrolyte Engineering with TFA- Anion-Rich Solvation Structure to Construct Highly Stable Zn2+/Na+ Dual-Salt Batteries.

Electrolyte engineering is recognized as an effective technique for high-performance aqueous zinc-ion rechargeable batteries, addressing difficulties such as free water decomposition, zinc anode corrosion, and zinc dendrite growth. Different from traditional strategies in aqueous electrolyte systems, this work focuses on organic electrolytes involving zinc trifluoroacetate hydrate (Zn(TFA)2·xH2O), sodium trifluoroacetate (NaTFA) dual-salt and acetonitrile (AN) solvent, in which trifluoroacetate anions (TFA- anions) have strong affinity toward zinc ions to form anion-rich solvates, thus inducing an inorganic-rich solid electrolyte interphase (SEI) to protect Zn from dendrite growth and side reactions. The Zn anode manifests long-term cycling over 2400 h at a current density of 0.5 mA cm-2 with a high Coulombic efficiency (CE) of 99.75%, showing an areal capacity as high as 5 mAh cm-2. Owing to the high reversibility of the sodium ions intercalation/deintercalation process in Na2MnFe(CN)6, the Zn//Na2MnFe(CN)6 full cells with the dual-salt electrolyte perform much better in terms of capacity retention than a device with Zn(TFA)2/AN electrolyte. This approach may open a new avenue for efficient zinc-ion rechargeable batteries via developing organic electrolytes.

Central post-stroke pain: advances in clinical and preclinical research.

Central poststroke pain (CPSP) is a medical complication that arises poststroke and significantly impacts the quality of life and social functioning of affected individuals. Despite ongoing research, the exact pathomechanisms of CPSP remain unclear, and practical treatments are still unavailable. Our review aims to systematically analyse current clinical and preclinical studies on CPSP, which is critical for identifying gaps in knowledge and guiding the development of effective therapies. The review will clarify the clinical characteristics, evaluation scales and contemporary therapeutic approaches for CPSP based on clinical investigations. It will particularly emphasise the CPSP model initiated by stroke, shedding light on its underlying mechanisms and evaluating treatments validated in preclinical studies. Furthermore, the review will not only highlight methodological limitations in animal trials but also offer specific recommendations to researchers to improve the quality of future investigations and guide the development of effective therapies. This review is expected to provide valuable insights into the current knowledge regarding CPSP and can serve as a guide for future research and clinical practice. The review will contribute to the scientific understanding of CPSP and help develop effective clinical interventions.

Niacin regulates glucose metabolism and osteogenic differentiation via the SIRT2-C/EBPß-AREG signaling axis.

The pathogenesis of osteoporosis is driven by several mechanisms including the imbalance between osteoblastic bone formation and osteoclastic bone resorption. Currently, the role of Niacin (NA), also known as vitamin B3, in the regulation of osteoblastic differentiation is not fully understood. Data from the NHANES database were employed to investigate the association of NA intake with the prevalence of osteoporosis. Alterations in mRNA and protein levels of genes and proteins involved in osteogenic differentiation were evaluated via techniques including qRT-PCR, protein immunoblotting, Alkaline Phosphatase (ALP) activity analysis, ALP staining, and Alizarin Red staining. Changes in the mouse skeletal system were investigated by organizational analysis and Micro-CT. The results indicated that NA promoted osteogenic differentiation. Co-immunoprecipitation and chromatin immunoprecipitation were performed to explore the underlying mechanisms. It was observed that NA promoted AREG expression by deacetylating C/EBPß via SIRT2, thereby activating the PI3K-AKT signaling pathway. It also enhanced the activity of the pivotal glycolytic enzyme, PFKFB3. This cascade amplified osteoblast glycolysis, facilitating osteoblast differentiation. These findings demonstrate that NA modulates glucose metabolism and influences osteogenic differentiation via the SIRT2-C/EBPß-AREG pathway, suggesting that NA may be a potential therapeutic agent for the management of osteoporosis, and AREG could be a plausible target.

Viral antibody response predicts morbidity and mortality in alcohol-associated hepatitis.

BACKGROUND AND AIMS: Alcohol-associated hepatitis (AH) is associated with very high mortality despite abstinence from alcohol; up to 40% of patients die within 6 months of diagnosis. Patients with AH are especially prone to infections, which can lead to multiorgan dysfunction and poorer prognosis. APPROACH AND RESULTS: We performed comprehensive serological profiling of the viral and bacterial infection history of 36 healthy controls, 48 patients with alcohol use disorder, and 224 patients with AH from 2 multicenter observational studies. We used systematic viral and bacterial epitope scanning by VirScan, a phage-display immunoprecipitation and sequencing technology that detects the peptides recognized by antibodies in patient sera, to comprehensively analyze antiviral and antibacterial antibodies and identify serologic biomarkers to predict patient outcomes. We found significant differences in the serological profiles of the 3 populations. The number of serum antibody epitopes in patients with alcohol use disorder during abstinence was increased compared with during active alcohol use. A decreased number and diversity of viral and bacterial antibody targets were detected in the sera of patients with AH, particularly those with a higher Child-Pugh score. In patients with AH, a decrease in the serum antiviral, but not antibacterial, antibody repertoire was associated with decompensation and mortality. Ninety-day mortality in AH could be predicted using a serum viral epitope signature. CONCLUSIONS: Abstinence from alcohol is associated with a significant increase in serum viral and bacterial antibody response. Decreased serum antiviral antibody repertoire is predictive of decompensation of liver disease and mortality in patients with AH.

Associations between Thyroid Hormones and Cognitive Impairment in Patients with Parkinson's Disease.

This study aims to explore the correlation of serum thyroid hormone levels to cognitive impairments in Parkinson's disease (PD) patients. In this retrospective study, 106 Chinese patients without cognitive impairments and 94 patients with cognitive impairments, including 55 with mild cognitive impairment (PD-MCI) and 39 with PD dementia (PDD), were analyzed. Clinical data regarding the PD assessments, including disease duration, Unified Parkinson's Disease Rating Scale (UPDRS) Part 3 scores, and Hoehn and Yahr (H-Y) staging, were analyzed. Cognitive functions were evaluated using the Montreal Cognitive Assessment score. Serum levels of thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3), were measured using ELISA. Significantly altered H-Y staging, disease duration, and UPDRS Part 3 scores were observed in PD patients with cognitive impairment compared with those without. Serum levels of FT3 were significantly decreased, while FT4 and TSH levels were significantly elevated in PD patients with cognitive impairment compared with those without. Combined detection of TSH, FT3, and FT4 showed value in distinguishing PD patients with and without cognitive impairment. Furthermore, a comparison of serum levels between PD-MCI and PDD patients revealed significant association between thyroid hormone levels and the degree of cognitive impairment in PD patients. Our findings suggest a relationship between changes in serum thyroid hormone levels and cognitive impairments in PD patients. Thyroid hormone levels, particularly FT3, may serve as potential markers for cognitive dysfunction in PD.

Nanopore Sequencing Technology: A Reliable Method for Pathogen Diagnosis in Elderly Patients with Community-Acquired Pneumonia.

Purpose: Next-generation sequencing of the metagenome (mNGS) is gaining traction as a valuable tool for diagnosing infectious diseases. Compared to mNGS, pathogen detection based on Oxford Nanopore Technology further shortens the detection time. This study seeks to assess the efficacy of Nanopore sequencing in identifying pathogens associated with community-acquired pneumonia (CAP) among elderly individuals in China. Patients and Methods: From January 2023 to June 2023, elderly patients with CAP were prospectively recruited from Hangzhou First People's Hospital. A comprehensive set of clinical data was gathered, and bronchoalveolar lavage (BAL) fluid samples were collected. Concurrently, pathogen identification was performed using conventional microbiological diagnostic methods, Illumina sequencing, and Nanopore sequencing, and the diagnostic efficacy of pathogen detection was compared. Results: The study included a total of 29 patients. The diagnostic positivity rates of traditional microbiological detection, Illumina sequencing, and Nanopore sequencing were 24.1%, 51.7%, and 48.3%, respectively. Their diagnostic specificities were 91.7%, 50%, and 75%, respectively. Compared to traditional microbiological detection, both Nanopore and Illumina sequencing showed significantly increased sensitivity. However, Nanopore sequencing exhibited relatively better consistency with the final clinical comprehensive diagnosis, with a Kappa value of 0.574. This outperformed traditional microbiological detection and Illumina sequencing, which had a Kappa value of 0.296 and 0.402, respectively. In addition, Nanopore sequencing required the shortest turnaround time. Conclusion: Nanopore sequencing technology demonstrates as a reliable and rapid method for detecting pathogens in elderly patients with CAP.

Microscopic in situ observation of electromechanical instability in a dielectric elastomer actuator utilizing transparent carbon nanotube electrodes.

Electromechanical instability (EMI) restricts the performance of dielectric elastomer actuators (DEAs), leading to premature electrical breakdown at a certain voltage. However, macro-level observations using traditional carbon grease electrodes have failed to capture the detailed features of EMI. In this study, we investigated EMI at the microscopic scale by fabricating transparent and conductive single-walled carbon nanotube (SWCNT) electrodes. Our findings reveal that EMI predominantly occurs in highly localized regions with dimensions on the order of tens of micrometers. This snap-through instability is likely induced by pre-existing defects within the elastomer, such as air voids or conductive particles, which reduce the critical voltage required for EMI in the flawed areas. From the perspective of phase transition principles, these defects act as heterogeneous nucleation sites for new phase embryos, thereby lowering the energy barrier for the electromechanical phase transition (i.e., EMI) compared to homogeneous nucleation in an ideally impurity-free elastomer. This study clarifies the longstanding discrepancy between theoretically predicted deformation bursts and the experimentally observed macroscopic continuous expansion of DEAs under low pre-stretch conditions. Additionally, it underscores the critical importance of material purity in mitigating electromechanical instability.

National trends and disparities in herpes zoster vaccination among US older adults with chronic obstructive pulmonary disease, 2008 to 2022.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a risk factor for herpes zoster. Vaccination can prevent or attenuate herpes zoster and its related complications. However, evidence regarding vaccine uptake among patients with COPD is limited. Therefore, this study aimed to evaluate trends in herpes zoster vaccination and characteristics associated with vaccination among US older adults with COPD. METHODS: Data from the 2008 to 2022 National Health Interview Survey were used. Participants aged ≥50 years were included. Joinpoint regression analysis was performed to analyze trends in herpes zoster vaccination. A multivariable logistic regression model was used to identify factors associated with vaccination. RESULTS: From 2008 to 2022, an increasing trend in herpes zoster vaccination was observed (average annual percent change = 15.10, P < .01). This increasing trend was also observed when stratified by age groups. Disparities in vaccination were found across several factors, including age, sex, race or ethnicity, region, educational level, health insurance, income, smoking status, perceived health status, and flu and pneumococcal vaccination. CONCLUSIONS: There has been an upward trend in herpes zoster vaccination over the past 15 years among older adults with COPD. Disparities across several characteristics existed, underscoring the necessity for targeted policies and interventions to promote equity in vaccination.

Microbial Community Structure and Metabolism of Xinjiang Fine-Wool Sheep based on High-Throughput Sequencing Technology.

It turns out that the more than trillion microorganisms living in the host's digestive tract are crucial for maintaining nutrient intake, environmental suitability, and physiological mechanism. Xinjiang fine-wool sheep is an exclusive breed for wool in China, which has excellent stress tolerance. In this study, we collected feces and blood samples of 20 Xinjiang fine-wool sheep under the same genetic characteristics, the Fine-Wool Sheep (FWS) group and the Control Fine-Wool Sheep (CFWS) group were set up according to the differs in phenotypic characteristics of their wool. By 16S rRNA amplicon sequence, ITS1 region amplicons and Targeted Metabolomics, we analyzed the microbial community structure of fecal microorganisms and Short Chain Fatty Acids (SCFAs) in serum of the Xinjiang fine-wool sheep. Fecal microbial sequencing showed that the bacterial composition and structure were similar between the two groups, whereas there were significant differences in the composition and structure of the fungal community. It was also found that the abundant of Neocallimastigomycota in the intestinal fungal community of FWS was higher. In addition, the results of the serum SCFAs content analysis showed that butyric acid was significantly differences than those two groups. Correlation analysis between SCFAs and bacteria found that butyric acid metabolism had positively correlated (P < 0.05) with Ruminococcus and UCG-005. Overall, our data provide more supplement about the gut microbes community composition and structure of the Xinjiang fine-wool sheep. These results might be useful for improving gut health of sheep and taking nutritional control measure to improve production traits of animals in future.

Oleandrin enhances radiotherapy sensitivity in lung cancer by inhibiting the ATM/ATR-mediated DNA damage response.

Despite active clinical trials on the use of Oleandrin alone or in combination with other drugs for the treatment of solid tumors, the potential synergistic effect of Oleandrin with radiotherapy remains unknown. This study reveals a new mechanism by which Oleandrin targets ATM and ATR kinase-mediated radiosensitization in lung cancer. Various assays, including clonogenic, Comet, immunofluorescence staining, apoptosis and Cell cycle assays, were conducted to evaluate the impact of oleandrin on radiation-induced double-strand break repair and cell cycle distribution. Western blot analysis was utilized to investigate alterations in signal transduction pathways related to double-strand break repair. The efficacy and toxicity of the combined therapy were assessed in a preclinical xenotransplantation model. Functionally, Oleandrin weakens the DNA damage repair ability and enhances the radiation sensitivity of lung cells. Mechanistically, Oleandrin inhibits ATM and ATR kinase activities, blocking the transmission of ATM-CHK2 and ATR-CHK1 cell cycle checkpoint signaling axes. This accelerates the passage of tumor cells through the G2 phase after radiotherapy, substantially facilitating the rapid entry of large numbers of inadequately repaired cells into mitosis and ultimately triggering mitotic catastrophe. The combined treatment of Oleandrin and radiotherapy demonstrated superior inhibition of tumor proliferation compared to either treatment alone. Our findings highlight Oleandrin as a novel and effective inhibitor of ATM and ATR kinase, offering new possibilities for the development of clinical radiosensitizing adjuvants.

Impact of campus closure during COVID-19 on lifestyle, educational performance, and anxiety levels of college students in China.

BACKGROUND: Higher education students exhibit heightened sensitivity to environmental changes as they navigate the critical transition from adolescence to adulthood. The coronavirus disease 2019 (COVID-19) pandemic has posed unprecedented challenges to universities worldwide, exemplifying a crisis that profoundly affects the learning outcomes and psychological status of college students. Although it is known that campus lockdown has triggered dramatic changes in lifestyles, learning outcomes, and psychological statuses, in-depth knowledge of the causal relationships among these changes remains largely unclear. METHODS: Here, we conducted a cross-sectional survey designed to assess the impact of campus closure during COVID-19 on lifestyle, educational performance, and anxiety levels among college students. We surveyed over 3,500 junior college, undergraduate and graduate participants from 94 colleges/universities across 30 provinces, municipalities, and autonomous regions in China.We employed structural equation modeling (SEM) to explore the relationships between changes in lifestyle, educational performance, and levels of anxiety associated with campus open or closure regulations during the COVID-19 pandemic. RESULTS: Our results discovered that sleep duration, physical activity involvement, and social connections were crucial for sustaining students' learning outcomes and mental health. The shift to online learning and campus lockdown exacerbated stressors, contributing to heightened anxiety (ß = 0.066), disrupted sleep patterns, and enhanced physical activity (ß = 0.070) and reduced learning effect (ß = -0.059). Sleep patterns were disrupted by the campus lockdown, an effect mediated by the degradation of relationships among classmates. Nonetheless, the best-fitting SEM uncovered the intricate relationships among lifestyle changes, learning outcomes, and psychological status in response to sudden environmental changes (Fisher's C = 80.949, P = 0.328). These results highlight the critical role of adaptable, supportive campus policies tailored to meet the diverse needs and interests of students during and beyond crises (Fisher's C = 59.568, P = 0.809). CONCLUSIONS: Our study advocates for a holistic approach that addresses the multifaceted aspects of student life to cultivate a resilient academic community. This approach contributes to a deeper understanding of the effects of sudden environmental changes on students' psychological well-being and academic performance in the post-pandemic era.

Ambient fine particulate matter and Life's essential 8 and mortality in adults in China: A Nationwide retrospective cohort study.

BACKGROUND: Enhanced cardiovascular health (CVH) is linked to reduced mortality risks, whereas long-term exposure to fine particulate matter (PM2.5), elevates these risks. Whether long-term exposure to PM2.5 counteracts the health benefits of high CVH is unknown. The study aims to evaluate whether the association of CVH assessed by Life's Essential 8 (LE8) with death was consistent between participants with different PM2.5 exposures. METHODS: We included 134,727 participants in the field survey of China Chronic Disease and Risk Factor Surveillance which was conducted from August 2013 to June 2014. The deaths of participants were obtained by linking to the National Mortality Surveillance System (2013-2018). The environmental data is obtained by satellite inversion. The participants' CVH scores were calculated using the LE8 method. Hazard ratio (HR) and 95% confidence intervals (95%CI) for mortality were calculated using Cox regression models. RESULTS: A total of 2,936 all-cause deaths and 1,158 cardiovascular disease (CVD) deaths were recorded. Compared to those with low CVH, adults with high CVH demonstrated a reduced risk of all-cause mortality, irrespective of their PM2.5 exposure levels (P < 0.05, all P for interaction >0.05). Furthermore, in comparison to those with low CVH and highest PM2.5 exposure, adults with high CVH and lowest PM2.5 exposure exhibited HR of 0.18 (95%CI, 0.12-0.25) for all-cause mortality and 0.13 (95%CI, 0.08-0.22) for CVD mortality. CONCLUSIONS: High CVH is associated with reduced all-cause mortality risk, regardless of PM2.5 exposure levels. For Chinese adults, sustaining high CVH is advisable, irrespective of their residential location.

[Biomanufacturing of propionic acid].

Propionic acid as an important C3 platform chemical has been widely used in food, pharmaceutical, and chemical fields. The chemical synthesis of propionic acid from petroleum and other chemical products has serious environmental pollution and is not sustainable. In recent years, the production of propionic acid by microbial transformation of renewable resources has received extensive attention. Focusing on the biomanufacturing of propionic acid, this paper firstly reviews the studies about the metabolic engineering of Propionibacterium and the pathway reconstruction in heterogeneous hosts such as Escherichia coli and Saccharomyces cerevisiae. Secondly, this paper reviews the recent progress in the synthesis of high-purity propionic acid from L-threonine or bio-based 1, 2-propanediol by the design and modification of the pathway of Pseudomonas putida KT2440 based on synthetic biology.

Pressure-Induced Exciton Formation and Superconductivity in Platinum-Based Mineral Sperrylite.

We report a comprehensive study of Sperrylite (PtAs2), the main platinum source in natural minerals, as a function of applied pressures up to 150 GPa. While no structural phase transition is detected from pressure-dependent X-ray measurements, the unit cell volume shrinks monotonically with pressure following the third-order Birch-Murnaghan equation of state. The mildly semiconducting behavior found in pure synthesized crystals at ambient pressures becomes more insulating upon increasing the applied pressure before metalizing at higher pressures, giving way to the appearance of an abrupt decrease in resistance near 3 K at pressures above 92 GPa consistent with the onset of a superconducing phase. The pressure evolution of the calculated electronic band structure reveals the same physical trend as our transport measurements, with a non-monotonic evolution explained by a hole band that is pushed below the Fermi energy and an electron band that approaches it as a function of pressure, both reaching a touching point suggestive of an excitonic state. A Lifshitz transition of the electronic structure and an increase in the density of states may naturally explain the onset of superconductivity in this material.

Type IV secretion system effector sabotages multiple defense systems in a competing bacterium.

Effector proteins secreted by bacteria that infect mammalian and plant cells often subdue eukaryotic host cell defenses by simultaneously affecting multiple targets. However, instances when a bacterial effector injected in the competing bacteria sabotage more than a single target have not been reported. Here, we demonstrate that the effector protein, LtaE, translocated by the type IV secretion system from the soil bacterium Lysobacter enzymogenes into the competing bacterium, Pseudomonas protegens, affects several targets, thus disabling the antibacterial defenses of the competitor. One LtaE target is the transcription factor, LuxR1, that regulates biosynthesis of the antimicrobial compound, orfamide A. Another target is the sigma factor, PvdS, required for biosynthesis of another antimicrobial compound, pyoverdine. Deletion of the genes involved in orfamide A and pyoverdine biosynthesis disabled the antibacterial activity of P. protegens, whereas expression of LtaE in P. protegens resulted in the near-complete loss of the antibacterial activity against L. enzymogenes. Mechanistically, LtaE inhibits the assembly of the RNA polymerase complexes with each of these proteins. The ability of LtaE to bind to LuxR1 and PvdS homologs from several Pseudomonas species suggests that it can sabotage defenses of various competitors present in the soil or on plant matter. Our study thus reveals that the multi-target effectors have evolved to subdue cell defenses not only in eukaryotic hosts but also in bacterial competitors.

Characterization of a novel multifunctional glycoside hydrolase family in the metagenome-assembled genomes of horse gut.

The gut microbiota is a treasure trove of carbohydrate-active enzymes (CAZymes). To explore novel and efficient CAZymes, we analyzed the 4,142 metagenome-assembled genomes (MAGs) of the horse gut microbiota and found the MAG117.bin13 genome (Bacteroides fragilis) contains the highest number of polysaccharide utilisation loci sites (PULs), indicating its high capability for carbohydrate degradation. Bioinformatics analysis indicate that the PULs region of the MAG117.bin13 genome encodes many hypothetical proteins, which are important sources for exploring novel CAZymes. Interestingly, we discovered a hypothetical protein (595 amino acids). This protein exhibits potential CAZymes activity and has a lower similarity to CAZymes, we named it BfLac2275. We purified the protein using prokaryotic expression technology and studied its enzymatic function. The hydrolysis experiment of the polysaccharide substrate showed that the BfLac2275 protein has the ability to degrade α-lactose (156.94 U/mg), maltose (92.59 U/mg), raffinose (86.81 U/mg), and hyaluronic acid (5.71 U/mg). The enzyme activity is optimal at pH 5.0 and 30 ℃, indicating that the hypothetical protein BfLac2275 is a novel and multifunctional CAZymes in the glycoside hydrolases (GHs). These properties indicate that BfLac2275 has broad application prospects in many fields such as plant polysaccharide decomposition, food industry, animal feed additives and enzyme preparations. This study not only serves as a reference for exploring novel CAZymes encoded by gut microbiota but also provides an example for further studying the functional annotation of hypothetical genes in metagenomic assembly genomes.