A Genomewide Evolution-Based CRISPR/Cas9 with Donor-Free (GEbCD) for Developing Robust and Productive Industrial Yeast.

Developing more robust and productive industrial yeast is crucial for high-efficiency biomanufacturing. However, the challenges posed by the long time required and the low abundance of mutations generated through genomewide evolutionary engineering hinder the development and optimization of desired hosts for industrial applications. To address these issues, we present a novel solution called the Genomewide Evolution-based CRISPR/Cas with Donor-free (GEbCD) system, in which nonhomologous-end-joining (NHEJ) repair can accelerate the acquisition of highly abundant yeast mutants. Together with modified rad52 of the DNA double-strand break repair in Saccharomyces cerevisiae, a hypermutation host was obtained with a 400-fold enhanced mutation ability. Under multiple environmental stresses the system could rapidly generate millions of mutants in a few rounds of iterative evolution. Using high-throughput screening, an industrial S. cerevisiae SISc-Δrad52-G4-72 (G4-72) was obtained that is strongly robust and has higher productivity. G4-72 grew stably and produced ethanol efficiently in multiple-stress environments, e.g. high temperature and high osmosis. In a pilot-scale fermentation with G4-72, the fermentation temperature was elevated by 8 °C and ethanol production was increased by 6.9% under the multiple stresses posed by the industrial fermentation substrate. Overall, the GEbCD system presents a powerful tool to rapidly generate abundant mutants and desired hosts, and offers a novel strategy for optimizing microbial chassis with regard to demands posed in industrial applications.

Mechanistic study of the effect of flexible fixation and load-bearing stress environment on fracture healing and shaping.

BACKGROUND: The biomechanical environment created by suture-button fixation Latarjet is conducive to the healing and shaping of the transplanted coracoid, but its mechanism remains unclear. The latest research has found that the absence of stem cell chemokine (CXCL12) impeded bone regeneration in Sonic Hedgehog (SHH)-deficient animals. However, whether the biomechanical environment affects SHH and CXCL12 function has not been studied. METHODS: Rat fracture models were constructed to simulate stress environments under non-load-bearing and load-bearing conditions. The fracture healing and shaping, as well as the expression levels of SHH and CXCL12, were assessed through gross viewing, micro-computed tomography (micro-CT), and histochemical staining. RESULTS: Under flexible fixation, the relative bone volume (BV/TV) of rats exposed to the load-bearing stress environment was significantly higher than that of rats under a non-load-bearing stress environment (p ≤ 0.05). Adverse bone shaping was not observed in rats subjected to flexible fixation. The levels of SHH and CXCL12 in load-bearing rats exhibited significant elevation (p ≤ 0.05). Under a load-bearing stress environment, no significant difference was observed in the BV/TV between the flexible fixation group and the rigid fixation group (p ≥ 0.05), but there was excessive hyperplasia of the fracture callus in the rigid fixation group. The levels of SHH and CXCL12 in rats subjected to rigid fixation were significantly elevated (p ≤ 0.05). CONCLUSIONS: Flexible fixation and load-bearing stress environment may contribute to bone healing and shaping by influencing the levels of SHH and CXCL12, suggested that this mechanism may be relevant to the healing and shaping of the transplanted coracoid after suture-button fixation Latarjet.

Mechanical Properties and Failure Mechanism of Anchored Bedding Rock Material under Impact Loading.

In view of the problem that anchored bedding rock material is prone to instability and failure under impact loading in the process of deep coal mining, and taking the lower roadway of a deep 2424 coal working face in the Suncun coal mine as the engineering background, a mechanical model of anchored bedding rock material was established, and the instability criterion of compression and shear failure of anchored bedding rock material was obtained. Then, the separated Hopkinson pressure bar was used to carry out an impact-loading test on the anchored bedding rock material, and the dynamic mechanical properties of the rock with different anchoring modes and bolt bedding angles were studied; the evolution law of the strain field of the anchored bedding rock material was also obtained. The results show the following: (1) The bolt support could effectively improve the dynamic load strength and dynamic elastic modulus of the rock material with anchorage bedding, the degree of improvement increased with the increase in the angle of the bolt bedding, and the full anchorage effect was much higher than the end anchorage effect was. (2) The bolt bedding angle and anchorage mode greatly influenced crack development and displacement characteristics. After an impact, the bedding rock material had obvious shear displacement along the bedding direction, and obvious macroscopic cracks were produced in the bedding plane. The research results offer theoretical guidance to and have reference significance for deep roadway anchorage support engineering.

White Rann of Kachchh harbours distinct microbial diversity reflecting its unique biogeography.

The understanding of sub-surface soil microbial diversity is limited at both saline and hypersaline ecosystems, even though salinity is found to affect the microbial community in aqueous and terrestrial environment. In this study, a phylo-taxonomy analysis as well as the functional characteristics of microbial community of flat salt basin of White Rann of Kachchh (WR), Gujarat, India was performed along the natural salinity gradient. The high throughput sequencing approach has revealed the numerical abundance of bacteria relative to the archaea. Salinity, TOC, EC and sulphate concentration might be the primary driver of the community distribution along the transect at WR. The much anticipated effect of salinity gradient on the microbial composition surprisingly turned out to be more speculative, with little variance in the community composition along the spatial distance of WR. The metabolic pathways involved in energy metabolism (like carbon, nitrogen, sulphur) along with environmental adaptive genes (like osmotic and oxidative stress response, heat and cold shock genes clusters) were abundantly annotated from shot-gun metagenomic study. The carbonic anhydrase harbouring bacteria Bacillus sp. DM4CA1 was isolated from WR, having a catalytic ability for converting the gaseous carbon dioxide in presence of calcium carbonate into calcite at 25 % higher rate as compared to non-harbouring strains. The enzyme has a role in multiple alternative pathways in microbial metabolism. With the array of results obtained, the study could become the new reference for understanding the diversity structure and functional characteristics of the microbial community of terrestrial saline environment.

Progress in studying heteromorphic leaves in Populus euphratica: leaf morphology, anatomical structure, development regulation and their ecological adaptation to arid environments.

Populus euphratica Oliv. is a tree that is strongly resistant to drought and salt stress, which is primarily distributed in arid and semiarid lands. The leaves of the species exhibit a special feature that causes them to be designated as heterophylly. In this brief review, we primarily discuss the heteromorphic leaf development and anatomical features, such as the differentiation of spongy and palisade tissues, in heteromorphic leaves of the species. Furthermore, we also discuss the different physiological characteristics in heteromorphic leaves related to the ecological adaptation of P. euphratica to drought environments. These traits in P. euphratica may help researchers evaluate its ecological value in arid areas and evaluate its scientific merit in understanding the mechanism of development of heteromorphic leaves in plants.

Preditores de sofrimento psicológico e prevalência de transtornos mentais autodeclarados em profissionais de saúde e na população em geral durante a pandemia de Covid-19 no Brasil / Predictors of psychological distress and prevalence of self-reported mental disorders in health care professionals and in the general population during the Covid-19 pandemic in Brazil

O fardo dos transtornos mentais pode aumentar durante a pandemia de Covid-19. Por isso, é estratégico caracterizar a saúde mental da população. Analisamos dados coletados pela Internet de 164.881 profissionais de saúde e 5.635 participantes da população geral. O Índice de Gravidade Global (GSI) do Inventário Breve de Sintomas, diagnóstico autodeclarado de transtornos mentais, características sociodemográficas, estado de saúde física, história de contato com a Covid-19, percepções e preocupações e medidas preventivas adotadas foram comparados entre as amostras. Análises de regressão múltipla foram usadas para investigação de fatores associados ao GSI. O distresse psicológico foi classificado como alto ou muito alto em 13,4% dos profissionais de saúde e em 31,4% dos participantes da população geral. A prevalência de transtornos mentais ao longo da vida foi 36% para profissionais de saúde e 44,7% para a população geral, sendo os mais frequentes transtornos depressivos e ansiedade generalizada. Entre os profissionais de saúde, ser do sexo feminino e mais jovem foi associado à maior distresse psicológico. Para a população geral foram preditores de distresse a classe econômica e um domicílio com mais pessoas. Foram significativamente associados ao GSI sintomas de Covid-19, sentir-se menos produtivo no trabalho, medo de transmitir o vírus para a família, medo de dificuldades financeiras e sentir que os relacionamentos em casa pioraram. A prevalência de transtornos mentais atinge parte relevante da população brasileira. Fatores sociodemográficos, aspectos familiares e instabilidade financeira devem ser considerados no entendimento do distresse psicológico durante a pandemia.(AU)

BACKGROUND: The burden of mental disorders is likely to increase during the Covid-19 pandemic. Knowing the rate of psychological distress and mental disorders, its severity, and factors associated with psychological distress is strategical. METHOD: We analyzed online cross-sectional data from 164,881 health professionals and from 5,635 participants from the general population in Brazil. The Global Severity Index (GSI) from the Brief Symptom Inventory, self-reported diagnosis of mental disorders, sociodemographic characteristics, and factors related to Covid-19, such as physical health status, diagnosis and contact history, perceptions and concerns, and precautionary measures were compared between samples. Multiple regression analysis was used to investigate factors related to GSI scores. RESULTS: Psychological distress was high or very high in 13.4% of health professionals and in 31.4% of the general population. Health professionals reported a lower rate of current or previous history of mental disorders (36%) than participants from the general population (44.7%). Age (younger) and gender (female) predicted higher psychological distress for health professionals and economic class (lower) and household size (more members) for the general population. People with higher GSI scores reported to have experienced more physical symptoms associated with Covid-19, feeling less productive at work, being afraid of transmitting the coronavirus to the family, fear of financial difficulties, and feeling that home relations were worse during the pandemic outbreak. CONCLUSIONS: Psychological distress at the first wave of Covid-19 was associated with sociodemographic features and an anxious perception of physical symptoms, virus transmission to loved ones, disruption of family relations, and financial situation.(AU)

INTRODUCCIÓN: Es probable que la carga de los trastornos mentales aumente durante la pandemia de Covid-19. Conocer la tasa de malestar psicológico y de los trastornos mentales, su gravedad y los factores asociados al malestar psicológico es estratégico. MÉTODO: Se analizaron datos transversales en línea de 164.881 profesionales de la salud y 5.635 participantes de la población general de Brasil. Se compararon entre las muestras el Índice de Gravedad Global (GSI) del Inventario Breve de Síntomas, el diagnóstico auto declarado de trastornos mentales, las características sociodemográficas y los factores relacionados con la Covid-19. Se utilizó un análisis de regresión múltiple para investigar los factores relacionados con las puntuaciones del GSI. RESULTADOS: El malestar psicológico era alto o muy alto en 13,4% de los profesionales de la salud y en 31,4% de la población general. Los profesionales de la salud declararon tasa de 36% de trastornos mentales y la población general de 44,7%. La edad (más joven) y el sexo (femenino) predijeron un mayor malestar psicológico para los profesionales de la salud y la clase económica (más baja) y el tamaño de la familia (más miembros) para la población general. Las personas con puntuaciones más altas en el GSI declararon haber experimentado más síntomas físicos asociados a la Covid-19, sentirse menos productivos en el trabajo, tener miedo de transmitir el coronavirus a la familia, temer dificultades económicas y sentir que las relaciones domésticas empeoraron. CONCLUSIONES: La angustia psicológica se asoció a las características sociodemográficas y a la percepción ansiosa de los síntomas físicos, la transmisión del virus a los seres queridos, la perturbación de las relaciones familiares y la situación económica.(AU)

Investigation of Chlorella vulgaris UTEX 265 Cultivation under Light and Low Temperature Stressed Conditions for Lutein Production in Flasks and the Coiled Tree Photo-Bioreactor (CTPBR).

Lutein has an increasing share in the pharmaceutical and nutraceutical market due to its benefits to eye health. Microalgae may be a potential source for lutein production while the expense limits the commercialization. In this study, a coiled tubular tree photobioreactor (CTPBR) design was investigated for cultivating the cold tolerant microalgae Chlorella vulgaris UTEX 265 under various conditions for lutein production. The influence and interaction of light irradiance strength, lighting cycle, and temperature on microalgae and lutein production efficiency at low temperature range were also studied in flasks via response surface method (RSM). The results demonstrated that 14 h day-light, 120 µmol photons m-2 s-1, and 10 °C was the optimal condition for algae growth and lutein production at low temperature experimental ranges. C. vulgaris UTEX 265 showed good potential to produce lutein in cold weather, and the optimum lutein production was contrary to the specific lutein content but corresponds to the trend of optimum growth. Additionally, fast growth (µ = 1.50 day-1) and good lutein recovery (11.98 mg g-1 day-1) in CTPBR were also achieved at the low irradiance stress condition and the low temperature photo-inhibition conditions.

Sazonalidade e qualidade do sêmen fresco e criopreservado de touros Pantaneiro e Nelore / Seasonality and quality of fresh and cryopreserved semen of Pantaneiro and Nellore bulls

Objetivou-se avaliar o efeito da estação do ano sobre a qualidade do sêmen fresco e criopreservado de reprodutores Pantaneiros (Bos taurus) criados em condições tropicais. Foram utilizados 7 touros Pantaneiros e 3 Nelores (controle), dos quais foi aferido circunferência escrotal, consistência testicular e após a coleta e congelamento do sêmen realizada análise de motilidade, vigor, defeitos menores, maiores e totais, concentração, integridade de membrana plasmática e acrossomal para sêmen fresco e além destas, estresse oxidativo para sêmen criopreservado. O experimento foi conduzido em delineamento inteiramente casualizado, e arranjo fatorial 2x2 (2 raças e 2 estações do ano). A raça, estação do ano ou a interação entre eles, não alteraram significativamente as médias de circunferência escrotal, consistência testicular, motilidade, vigor, concentração, integridade de membrana acrossomal e porcentagem de defeitos menores. A integridade da membrana plasmática no sêmen fresco sofreu efeito da estação do ano e foi menor no inverno em ambas raças (95,76 ± 1,77% vs. 87,07 ± 4,78% P=0,03). A estação do inverno aumentou a porcentagem de defeitos maiores (29,15% vs. 16,44%, P<0,01) e totais (17,49% vs. 30,45%, P<0,01). Os parâmetros do sêmen congelado não foram influenciados pela raça, estação do ano ou interação entre elas. Portanto, nas condições edafoclimáticas estudadas, os reprodutores Pantaneiros apresentaram redução na sua qualidade seminal na estação do inverno.

The aim of the present study was to evaluate the effect of seasonality on the quality of fresh and cryopreserved semen of Pantaneiro breed (Bos taurus) bulls raised under tropical conditions. Scrotal circumference and testicular consistency were performed in seven Pantaneiro and three Nellore (control) bulls. Sperm motility, vigor, minor, major and total defects, concentration, plasma and acrosomal membrane integrity were assessed in fresh and post-thawed semen. Additionally, oxidative stress was determined in post-thawed semen samples. The experiment was done in a complete randomized design, with a 2x2 factorial arrangement (2 breeds and 2 seasons). Breed, season of the year or the interaction of both did not alter scrotal circumference, testicular consistency, motility, vigor, concentration, acrosomal membrane integrity and percentage of minor defects (P<0.05). Plasma membrane integrity of fresh semen was affected by the season and was smaller in winter in both breeds (95.76 ± 1.77% vs 87.07 ± 4.78%, P=0.03). Nevertheless, also in the winter there was an increase in the percentage of major (29.15% vs 16.44%, P<0.01) and total defects (17.49% vs. 30.45%, P<0.01) in fresh semen samples. Breed, season or interaction of both did not influence the sperm parameters of cryopreserved semen. Thus, in the studied climatic conditions, the Pantaneiro breed bulls present decrease in semen quality mainly in the winter season

Effect of low stress environment on repairing of children necrotic femoral head / 中国矫形外科杂志

[Objective]To observe the change of children necrotic femoral head repairing under low stress environment and to explore the effect of low stress environment on Perthes disease.[Method]The sick coxa was supported by Coxa Multi-functional External Fixation Shoring Fixator,which decreased femoral head stress and creates a low-stress environment for the sick coxa.Meanwhile,the affected extremity was kept abduction and internal rotation in order to increase femoral head containment.The coxa could flex and extend partly on sagittal plane.Twenty-eight patients(32 hips) were followed up with mean follow-up time of 3 years and 5 months(2~7 years).The radiological characteristics of pre-and post-operation was analyzed.[Result]At 3 months postoperatively,joint space was broadened,high density necrosis shadow became little and little,the femoral head became full,height of the femoral head epiphysis increased.If epiphyseal nucleus fragmentation vaded epiphyseal plate,the big head and pachy-neck and the subluxation of coxa would finally result.[Conclusion]Under low stress environment,child necrotic femoral head could be repaired.The prognosis is related to Catterall stage of Perthes disease.On Catterall Ⅱ and Ⅲ stage,the curative effect is fairly good.But on Catterall Ⅳ stage,the curative effect is not evident.