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Background The efficacy of neoadjuvant treatment with epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) monotherapy in patients with stage III-N2 EGFR-mutant remains unsatisfactory. This study explored the potential benefits of combining first-generation EGFR-TKI with chemotherapy as a neoadjuvant treatment for patients with stage III-N2 EGFR-mutant non-small cell lung cancer (NSCLC). Patients and Methods The medical records of patients with III-N2 EGFR-mutant NSCLC who received neoadjuvant therapy with EGFR-TKI at Shanghai Chest Hospital from October 2011 to October 2022 were retrospectively reviewed. Patients with stage III-N2 EGFR-mutant NSCLC who received first-generation TKI combined with chemotherapy as neoadjuvant treatment were included in the combination group, and those who received EGFR-TKI monotherapy were included in the monotherapy group. The study assessed the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, disease-free survival (DFS), overall survival (OS), downstaging rates of pathologic lymph nodes (from stage N2 to N1 or N0), major pathologic response (MPR) rate, pathological complete response (PCR) rate, and safety. Results A total of 74 631 patients with EGFR-mutant NSCLC were screened, and 60 patients were included, 7 of whom did not undergo surgery after neoadjuvant targeted therapy. Of the remaining 53 patients, 15 received first-generation EGFR-TKI combined with chemotherapy as neoadjuvant treatment, and 38 received EGFR-TKI monotherapy. The median follow-up time was 44.12 months. The ORR was 50.0% (9/18) in the combination group and 40.5% (17/42) in the monotherapy group (P  = .495). The MPR rate was 20.0% (3/15) and 10.5% (4/38) in the combination and monotherapy groups, respectively (P  = .359). No patients achieved PCR in the combination group, while 3 (7.89%) attained PCR in the monotherapy group. The 2 groups did not differ in N2 downstaging rate (P  = .459). The median DFS was not reached in the combination group, while it was 23.6 months (95% CI: 8.16-39.02) in the monotherapy group (P  = .832). Adverse events observed were consistent with those commonly associated with the 2 treatments. Conclusion Combination therapy with first-generation EGFR-TKI and chemotherapy could be considered a neoadjuvant treatment option for patients with stage III-N2 EGFR-mutant NSCLC, exhibiting acceptable toxicity. However, regarding short-term efficacy, combination therapy did not demonstrate superiority over EGFR-TKI monotherapy. Long-term follow-up is warranted for a more accurate assessment of the DFS and OS. [ABSTRACT FROM AUTHOR]

Artificial diets for silkworms overcome the seasonal limitations of traditional rearing methods with fresh mulberry leaves. However, the current wet artificial diets, steamed at high temperatures, are not favored by silkworms, and they are cumbersome and challenging to preserve. These conditions adversely affected the development of artificial diet-based sericulture production. In this study, we disinfected dry powder diets with radiation and added distilled water without steaming before use. Then, the nutritional value of finished diets and their impact on silkworm development was assessed. Compared with steamed diets, nonsteamed diets were more attractive to silkworms. Chemical assays showed significantly more essential nutrients for silkworms, including l -ascorbic acid, vitamin B1, vitamin B2, and urease in nonsteamed diets than in steamed diets. Feeding fifth-instar silkworm larvae with nonsteamed diets significantly improved the ammonia utilization efficiency of the diet and increased the cocoon shell rate and diet/silk protein conversion efficiency by 5.9% and 13.3%, respectively. When fed with nonsteamed diets, the abundance of aerobic microorganisms in silkworm intestines increased and the abundance of pathogenic bacteria decreased. Furthermore, the vitality of the silkworm, measured by the dead worm cocoon rate, significantly improved by 16.90%. In summary, preparing sterile wet diets without high-temperature steaming effectively improved the nutritional value of the diet and enhanced silkworm growth. [ABSTRACT FROM AUTHOR]

Environmental stresses severely affect plant growth and crop productivity. Regulated by 14-3-3 proteins (14-3-3s), H+-ATPases (AHAs) are important proton pumps that can induce diverse secondary transport via channels and co-transporters for the abiotic stress response of plants. Many studies demonstrated the roles of 14-3-3s and AHAs in coordinating the processes of plant growth, phytohormone signaling, and stress responses. However, the molecular evolution of 14-3-3s and AHAs has not been summarized in parallel with evolutionary insights across multiple plant species. Here, we comprehensively review the roles of 14-3-3s and AHAs in cell signaling to enhance plant responses to diverse environmental stresses. We analyzed the molecular evolution of key proteins and functional domains that are associated with 14-3-3s and AHAs in plant growth and hormone signaling. The results revealed evolution, duplication, contraction, and expansion of 14-3-3s and AHAs in green plants. We also discussed the stress-specific expression of those 14-3-3 and AHA genes in a eudicotyledon (Arabidopsis thaliana), a monocotyledon (Hordeum vulgare), and a moss (Physcomitrium patens) under abiotic stresses. We propose that 14-3-3s and AHAs respond to abiotic stresses through many important targets and signaling components of phytohormones, which could be promising to improve plant tolerance to single or multiple environmental stresses. [ABSTRACT FROM AUTHOR]

The sustainable production of crops faces increasing challenges from global climate change and human activities, which leads to increasing instances of many abiotic stressors to plants. Among the abiotic stressors, drought, salinity and excessive levels of toxic metals cause reductions in global agricultural productivity and serious health risks for humans. Cytokinins (CKs) are key phytohormones functioning in both normal development and stress responses in plants. Here, we summarize the molecular mechanisms on the biosynthesis, metabolism, transport and signaling transduction pathways of CKs. CKs act as negative regulators of both root system architecture plasticity and root sodium exclusion in response to salt stress. The functions of CKs in mineral-toxicity tolerance and their detoxification in plants are reviewed. Comparative genomic analyses were performed to trace the origin, evolution and diversification of the critical regulatory networks linking CK signaling and abiotic stress. We found that the production of CKs and their derivatives, pathways of signal transduction and drought-response root growth regulation are evolutionarily conserved in land plants. In addition, the mechanisms of CK-mediated sodium exclusion under salt stress are suggested for further investigations. In summary, we propose that the manipulation of CK levels and their signaling pathways is important for plant abiotic stress and is, therefore, a potential strategy for meeting the increasing demand for global food production under changing climatic conditions. [ABSTRACT FROM AUTHOR]

Drought significantly affects stomatal regulation, leading to the reduced growth and productivity of plants. Plant 14-3-3 proteins were reported to participate in drought response by regulating the activities of a wide array of target proteins. However, the molecular evolution, expression pattern and physiological functions of 14-3-3s under drought stress remain unclear. In this study, a comparative genomic analysis and the tissue-specific expression of 14-3-3s revealed the highly conserved and early evolution of 14-3-3s in green plants and duplication and expansion of the 14-3-3s family members in angiosperms. Using barley (Hordeum vulgare) for the functional characterization of 14-3-3 proteins, the transcripts of five members out of six Hv14-3-3s were highly induced by drought in the drought-tolerant line, XZ141. Suppression of the expression of Hv14-3-3A through barley stripe mosaic virus-virus induced gene silencing resulted in significantly increased drought sensitivity and stomatal density as well as significantly reduced net CO2 assimilation (A) and stomatal conductance (gs) in barley. Moreover, we showed the functional interactions between Hv14-3-3s and key proteins in drought and stomatal responses in plants—such as Open Stomata 1 (HvOST1), Slow Anion Channel 1 (HvSLAC1), three Heat Shock Proteins (HvHSP90-1/2/5) and Dehydration-Responsive Element-Binding 3 (HvDREB3). Taken together, we propose that 14-3-3s are highly evolutionarily conserved proteins and that Hv14-3-3s represent a group of the core regulatory components for the rapid stomatal response to drought in barley. This study will provide important evolutionary and molecular evidence for future applications of 14-3-3 proteins in breeding drought-tolerant crops in a changing global climate. [ABSTRACT FROM AUTHOR]

To investigate the expression and roles of TAM (Tyro3/Axl/Mer) receptor tyrosine kinases (TK) in synovial fluid and synovial tissue of patients with rheumatoid arthritis (RA). The expression of TAM TKs in the synovial fluid and synovial tissues of RA and osteoarthritis (OA) patients was measured by ELISA and immunohistochemistry. The relationships between soluble TAM TKs (sTAM TKs) levels and the clinical features, laboratory parameters and disease activity were analyzed in RA. The concentrations of sTAM TK in the synovial fluids of RA patients were increased in comparison to those of OA patients. Compared with OA patients, the expression of membrane Tyro3 TK (mTyro3 TK) and mMer TK in RA patient synovial tissue were significantly increased, which may partly explain the possible mechanism of elevated levels of sTAM TK in RA patient synovial fluid. sAxl TK levels were decreased in RA patients under sulfasalazine treatment and elevated in patients under Iguratimod treatment. Furthermore, sTyro3 TK levels were positively correlated with erythrocyte sedimentation rate (ESR) and negatively correlated with white blood cells (WBCs), red blood cells (RBCs), and hemoglobin (HB) in RA patients. The levels of sMer TK were positively associated with disease duration and rheumatoid factor (RF) and negatively correlated with HB, complement 3 (C3), and C4. Taken together, TAM TKs might be involved in RA synovial tissue inflammation. [ABSTRACT FROM AUTHOR]

Objective The aim of this observational cohort study was to assess the effectiveness and safety of the IL-6-receptor inhibitor tocilizumab (TCZ) in Behçet's syndrome (BS) with refractory arterial involvement. Methods Ten patients admitted to the Rheumatology and Immunology Department of Peking University People's Hospital between January 2014 and December 2019 were enrolled. The enrolled patients met the BS international criteria and exhibited severe arterial impairments. Refractory arterio-BS was diagnosed based on objective vascular symptoms unexplainable by other known illnesses, and resistance to traditional immunosuppressants and glucocorticoids after 12 weeks. Patients received 8 mg/kg TCZ infusions every 4 weeks for ≥24 weeks, with simultaneous continuation of immunosuppressants and glucocorticoids. Clinical and imaging data were assessed before and after TCZ treatment. Results The enrolled patients were men aged 44.3 (10.5) years; the median disease duration was 186.5 (45.7) months, and the average age of arterial impairment onset was 38.7 (12.9) years. The following trends were observed: improvement and maintenance of symptoms after the 26.8 (7.2)-month follow-up, n  = 9; complete remission, n  = 6; partial response, n  = 3; immunosuppressant dose reduction, n  = 4; radiologic improvement of arterial lesions, n  = 4; and TCZ discontinuation owing to enlarged abdominal aortic aneurysm relapse, n  = 1. The average daily glucocorticoid dose reduced from 54.5 (20.6) to 8.3 (3.6) mg/d (P  < 0.001), while the median ESR and CRP values reduced from 50 (2–82) mm/h and 32.9 (2.1–62.3) mg/dl to 4 (1–10) mm/h and 2.9 (0.2–12.1) mg/dl, respectively (P  < 0.001). No TCZ-associated side effects were noted. Conclusion TCZ proved to be safe and effective for refractory arterial lesions in BS, with a steroid- and immunosuppressant-sparing benefit. [ABSTRACT FROM AUTHOR]

We compared how stomatal morphology and physiology control intrinsic leaf water use efficiency (iWUE) in two C3 and six C4 grasses grown at ambient (400 µmol mol–1) or glacial CO2 (180 µmol mol–1) and high (1000 µmol m–2 s–1) or low light intensity (200 µmol m–2 s–1). C4 grasses tended to have higher iWUE and CO2 assimilation rates, and lower stomatal conductance (g s), operational stomatal aperture (a op), and guard cell K+ influx rate relative to C3 grasses, while stomatal size (SS) and stomatal density (SD) did not vary according to the photosynthetic type. Overall, iWUE and g s depended most on a op and density of open stomata. In turn, a op correlated with K+ influx, stomatal opening speed on transition to high light, and SS. Species with higher SD had smaller and faster-opening stomata. Although C4 grasses operated with lower g s and a op at ambient CO2, they showed a greater potential to open stomata relative to maximal stomatal conductance (g max), indicating heightened stomatal sensitivity and control. We uncovered promising links between a op, g s, iWUE, and K+ influx among C4 grasses, and differential K+ influx responses of C4 guard cells to low light, revealing molecular targets for improving iWUE in C4 crops. [ABSTRACT FROM AUTHOR]

Oryza coarctata is the only wild rice species with significant salinity tolerance. The present work examines the role of the substantial rhizomatous tissues of O. coarctata in conferring salinity tolerance. Transition to an erect phenotype (shoot emergence) from prostrate growth of rhizome tissues is characterized by marked lignification and suberization of supporting sclerenchymatous tissue, epidermis, and bundle sheath cells in aerial shoot-proximal nodes and internodes in O. coarctata. With salinity, however, aerial shoot-proximal internodal tissues show reductions in lignification and suberization, most probably related to re-direction of carbon flux towards synthesis of the osmporotectant proline. Concurrent with hypolignification and reduced suberization, the aerial rhizomatous biomass of O. coarctata appears to have evolved mechanisms to store Na+ in these specific tissues under salinity. This was confirmed by histochemical staining, quantitative real-time reverse transcription–PCR expression patterns of genes involved in lignification/suberization, Na+ and K+ contents of internodal tissues, as well as non-invasive microelectrode ion flux measurements of NaCl-induced net Na+, K+, and H+ flux profiles of aerial nodes were determined. In O. coarctata , aerial proximal internodes appear to act as 'traffic controllers', sending required amounts of Na+ and K+ into developing leaves for osmotic adjustment and turgor-driven growth, while more deeply positioned internodes assume a Na+ buffering/storage role. [ABSTRACT FROM AUTHOR]

Primary malignant bone tumors can be life-threatening. Surgical resection of tumor plus chemotherapy is the standard clinical treatment. However, postoperative recovery is hindered due to tumor recurrence caused by residual tumor cells and bone defect caused by resection of tumor tissue. Herein, a multifunctional mussel-inspired film was fabricated on Mg alloy, that is, an inner hydrothermal-treated layer, a middle layer of polydopamine, and an outer layer of doxorubicin. The modified Mg alloy showed excellent photothermal effect and thermal/pH-controlled release of doxorubicin. The synergistic effect of chemotherapy and photothermal therapy enabled the modified Mg alloy to kill bone tumor in vitro and inhibit tumor growth in nude mice. Moreover, because of the controlled release of Mg ions and biocompatibility of polydopamine, the modified Mg alloy supported extracellular matrix mineralization, alkaline phosphatase activity, and bone-related gene expression in C3H10T1/2. Bone implantation model in rats verified that the modified Mg showed excellent osteointegration. These findings prove that the use of mussel-inspired multifunction film on Mg alloy offers a promising strategy for the therapy of primary malignant bone tumor. [ABSTRACT FROM AUTHOR]

Optical films that alter light transmittance may reduce energy consumption in high-tech greenhouses, but their impact on crop physiology remains unclear. We compared the stomatal responses of Capsicum plants grown hydroponically under control glass (70% diffuse light) or the smart glass (SG) film ULR-80, which blocked >50% of short-wave radiation and ~9% of photosynthetically active radiation (PAR). SG had no significant effects on steady-state (g s) or maximal (g max) stomatal conductance. In contrast, SG reduced stomatal pore size and sensitivity to exogenous abscisic acid (ABA), thereby increasing rates of leaf water loss, guard cell K+ and Cl– efflux, and Ca2+ influx. SG induced faster stomatal closing and opening rates on transition between low (100 µmol m–2 s–1) and high PAR (1500 µmol m–2 s–1), which compromised water use efficiency relative to control plants. The fraction of blue light (0% or 10%) did not affect g s in either treatment. Increased expression of stomatal closure and photoreceptor genes in epidermal peels of SG plants is consistent with fast stomatal responses to light changes. In conclusion, stomatal responses of Capsicum to SG were more affected by changes in light intensity than spectral quality, and re-engineering of the SG should maximize PAR transmission, and hence CO2 assimilation. [ABSTRACT FROM AUTHOR]

The initial aim of environmental epidemiology is to estimate the causal effects of environmental exposures on health outcomes. However, due to lack of enough covariates in most environmental data sets, current methods without enough adjustments for confounders inevitably lead to residual confounding. We propose a negative-control exposure based on a time-series studies (NCE-TS) model to effectively eliminate unobserved confounders using an after-outcome exposure as a negative-control exposure. We show that the causal effect is identifiable and can be estimated by the NCE-TS for continuous and categorical outcomes. Simulation studies indicate unbiased estimation by the NCE-TS model. The potential of NCE-TS is illustrated by 2 challenging applications: We found that living in areas with higher levels of surrounding greenness over 6 months was associated with less risk of stroke-specific mortality, based on the Shandong Ecological Health Cohort during January 1, 2010, to December 31, 2018. In addition, we found that the widely established negative association between temperature and cancer risks was actually caused by numbers of unobserved confounders, according to the Global Open Database from 2003–2012. The proposed NCE-TS model is implemented in an R package (R Foundation for Statistical Computing, Vienna, Austria) called NCETS, freely available on GitHub. [ABSTRACT FROM AUTHOR]

A novel magnetic solid-phase extraction technique coupled to ultraperformance liquid chromatography has been developed for separation and preconcentration of four sulfonylurea herbicides (sulfosulfuron, bensulfuron-methyl, pyrazosulfuron-ethyl and halosulfuro-methyl) in aqueous samples. The key point of this method was the application of a novel magnetic nanomaterial that composed of a low eutectic solvent as a shell coated on the magnetic core modified by polydopamine. The extensive active sites outside the low eutectic solvent can effectively adsorb the target herbicide in the extraction process. The obtained magnetic adsorbent was characterized with fourier transform infrared spectrometry, scanning electron microscopy and vibrating sample magnetometer. The influence parameters relevant to this method were optimized. Under the optimum conditions, good linearities could be obtained within the range of 1.0–200 μg L−1 for all analytes, with correlation coefficients ≥0.9908. The limit of detections of the method was between 0.0074 and 0.0100 μg L−1 and the relative standard deviations were 1.1–3.6%. The enrichment factor is 66.6. In the final experiment, the proposed method was successfully applied to the analysis of sulfonylurea herbicides residue in environment and drinking-water samples, and the obtained recoveries were between 70.6% and 109.4%. [ABSTRACT FROM AUTHOR]

Potassium (K+) is the major cationic inorganic nutrient utilized for osmotic regulation, cell growth, and enzyme activation in plants. Inwardly rectifying K+ channel 1 (AKT1) is the primary channel for root K+ uptake in plants, but the function of HvAKT1 in barley plants under drought stress has not been fully elucidated. In this study, we conducted evolutionary bioinformatics, biotechnological, electrophysiological, and biochemical assays to explore molecular mechanisms of HvAKT1 in response to drought in barley. The expression of HvAKT1 was significantly up-regulated by drought stress in the roots of XZ5—a drought-tolerant wild barley genotype. We isolated and functionally characterized the plasma membrane-localized HvAKT1 using Agrobacterium -mediated plant transformation and Barley stripe mosaic virus -induced gene silencing of HvAKT1 in barley. Evolutionary bioinformatics indicated that the K+ selective filter in AKT1 originated from streptophyte algae and is evolutionarily conserved in land plants. Silencing of HvAKT1 resulted in significantly decreased biomass and suppressed K+ uptake in root epidermal cells under drought treatment. Disruption of HvAKT1 decreased root H+ efflux, H+-ATPase activity, and nitric oxide (NO) synthesis, but increased hydrogen peroxide (H2O2) production in the roots under drought stress. Furthermore, we observed that overexpression of HvAKT1 improves K+ uptake and increases drought resistance in barley. Our results highlight the importance of HvAKT1 for root K+ uptake and its pleiotropic effects on root H+-ATPase, and H2O2 and NO in response to drought stress, providing new insights into the genetic basis of drought tolerance and K+ nutrition in barley. [ABSTRACT FROM AUTHOR]

Motivation Chromosomal patterning of gene expression in cancer can arise from aneuploidy, genome disorganization or abnormal DNA methylation. To map such patterns, we introduce a weighted univariate clustering algorithm to guarantee linear runtime, optimality and reproducibility. Results We present the chromosome clustering method, establish its optimality and runtime and evaluate its performance. It uses dynamic programming enhanced with an algorithm to reduce search-space in-place to decrease runtime overhead. Using the method, we delineated outstanding genomic zones in 17 human cancer types. We identified strong continuity in dysregulation polarity—dominance by either up- or downregulated genes in a zone—along chromosomes in all cancer types. Significantly polarized dysregulation zones specific to cancer types are found, offering potential diagnostic biomarkers. Unreported previously, a total of 109 loci with conserved dysregulation polarity across cancer types give insights into pan-cancer mechanisms. Efficient chromosomal clustering opens a window to characterize molecular patterns in cancer genome and beyond. Availability and implementation Weighted univariate clustering algorithms are implemented within the R package 'Ckmeans.1d.dp' (4.0.0 or above), freely available at https://cran.r-project.org/package=Ckmeans.1d.dp. Supplementary information Supplementary data are available at Bioinformatics online. [ABSTRACT FROM AUTHOR]

Aluminum (Al) toxicity is the primary limiting factor of crop production on acid soils. Tibetan wild barley germplasm is a valuable source of potential genes for breeding barley with acid and Al tolerance. We performed microRNA and RNA sequencing using wild (XZ16, Al-tolerant; XZ61, Al-sensitive) and cultivated (Dayton, Al-tolerant) barley. A novel homeobox-leucine zipper transcription factor, HvHOX9 , was identified as a target gene of miR166b and functionally characterized. HvHOX9 was up-regulated by Al stress in XZ16 (but unchanged in XZ61 and Dayton) and was significantly induced only in root tip. Phylogenetic analysis showed that HvHOX9 is most closely related to wheat TaHOX9 and orthologues of HvHOX9 are present in the closest algal relatives of Zygnematophyceae. Barley stripe mosaic virus-induced gene silencing of HvHOX9 in XZ16 led to significantly increased Al sensitivity but did not affect its sensitivity to other metals and low pH. Disruption of HvHOX9 did not change Al concentration in the root cell sap, but led to more Al accumulation in root cell wall after Al exposure. Silencing of HvHOX 9 decreased H+ influx after Al exposure. Our findings suggest that miR166b /HvHOX9 play a critical role in Al tolerance by decreasing root cell wall Al binding and increasing apoplastic pH for Al detoxification in the root. [ABSTRACT FROM AUTHOR]

Study Question: What is the impact of glucocorticoid (GC) on female reproduction?Summary Answer: Corticosterone (CORT) exposure causes little damage to oocyte quality or developmental competence but has an adverse effect on the uterus, which causes decreased implantation, embryo death and subsequent infertility.What Is Known Already: Chronic treatment with high GC doses is effective in controlling most allergic diseases but may lead to metabolic disorders such as obesity that are closely related with reproductive function.Study Design, Size, Duration: Hypercortisolism was induced in a female mouse model by supplementing the drinking water with 100 μg/ml of CORT. Controls received vehicle (1% v/v ethanol) only. After 4 weeks treatment mice were either mated or killed in estrus for hormone and organ measurements. In the first experiment, treatment with CORT or control continued during pregnancy but in the second CORT treatment was stopped after mating. To identify the effects of GC exposure on the uterus, blastocysts were generated by IVF of oocytes from CORT and control mice and replaced into recipients receiving the opposite treatment.Participants/materials, Setting, Methods: The effects of hypercortisolism on female mice were first characterized by living body fat content, body weight, food intake, hormone and biochemical measurements, a glucose tolerance test and an insulin resistance test. Fertility was determined with or without CORT-treatment during pregnancy. Oocyte quality was assessed by oocyte maturation, mitochondrial distribution, reactive oxygen species production, mitochondrial DNA mutations and morphology of blastocysts produced in vivo or in vitro. Blastocyst cross-transfer was done to evaluate the causes of embryonic development failure. Fetus development and uterus morphology evaluation as well as culture of oocytes in vitro with gradient concentrations of CORT were also carried out.Main Results and the Role Of Chance: In the hypercortisolism female mouse model, body weight and food intake were much higher than in the control, and corticosterone, estradiol, cholesterol (CHO) and triglycerides (TG) in the plasma of CORT-treated mice was significantly increased. The hypercortisolism female mice were infertile when CORT-treatment was sustained during pregnancy but fertile if CORT-treatment was stopped after mating. The rate of successful implantation in hypercortisolism mice with sustained CORT-treatment during pregnancy was significantly lower than in the control, and the implanted embryos could not develop beyond 13.5 dpc. Blastocyst cross-transfer showed that blastocysts from CORT-treated mice could develop to term in the uterus of control mice, but blastocysts from control mice failed to develop to term when they were transferred into CORT-treated mice, providing evidence that the infertility was mainly caused by an altered uterine environment. CORT administration did not affect oocyte maturation, mitochondrial distribution, ROS production and blastocyst morphology, but increased mitochondrial DNA mutations. Culture of oocytes in vitro with gradient concentrations of CORT showed that only very high concentrations of CORT caused damage to oocyte developmental competence.Large Scale Data: NA.Limitations, Reasons For Caution: The mouse model has the advantages of a consistent genetic and physiological background and openness to experimental manipulation over clinical studies but may not represent the human situation.Wider Implications Of the Findings: Our findings show that special care should be taken when administering CORT during pregnancy, and provide important information concerning female reproduction when treating patients by subjecting them to chronic GC exposure.Study Funding/competing Interest(s): This study was supported by the National Key R&D Program of China (Nos. 2016YFA0100400 and 2017YFC1000600) and the National Natural Science Foundation of China (31472055). The authors have no conflicts of interest. [ABSTRACT FROM AUTHOR]

Under environmental stresses, Haematococcus pluvialis accumulates large amounts of carotenoids. Scale of carotenoid biosynthesis depends on availability of geranylgeranyl pyrophosphate (GGPP) precursor, which is supplied by GGPP synthase (GGPPS) through sequential 1′-4 condensation of three isopentenyl pyrophosphates (IPPs) into dimethylallyl pyrophosphate (DMAPP). Using IPP and DMAPP as substrates, a tri-functional HpGGPPS was identified in this study to promiscuously synthesize allylic prenyl pyrophosphates (PPPs), e.g. C10 geranyl pyrophosphate (GPP), C15 farnesyl pyrophosphate (FPP), and C20 GGPP. Intriguingly, HpGGPPS can utilize GPP or FPP as a single substrate to synthesize GGPP by hydrolyzing the allylic PPP substrate into C5 IPP. Transcription of HpGGPPS and key carotenogenesis genes, morphological transformation, and carotenoid biosynthesis were differentially induced by environmental stresses, while HpGGPPS's products were low in vivo, implying that most of PPP flux had been shunted into carotenoid biosynthesis. Hydrolyzing allylic PPP intermediates into C5 building blocks by promiscuous HpGGPPS may be a fail safe for carotenoid accumulation against environmental stress. [ABSTRACT FROM AUTHOR]

Our previous studies showed that high salt tolerance in Tibetan wild barley accessions was associated with HvHKT1;1, a member of the high-affinity potassium transporter family. However, molecular mechanisms of HvHKT1;1 for salt tolerance and its roles in K+/Na+ homeostasis remain to be elucidated. Functional characterization of HvHKT1;1 was conducted in the present study. NaCl-induced transcripts of HvHKT1;1 were significantly higher in the roots of Tibetan wild barley XZ16 relative to other genotypes, being closely associated with its higher biomass and lower tissue Na+ content under salt stress. Heterologous expression of HvHKT1;1 in Saccharomyces cerevisiae (yeast) and Xenopus laevis oocytes showed that HvHKT1;1 had higher selectivity for Na+ over K+ and other monovalent cations. HvHKT1;1 was found to be localized at the cell plasma membrane of root stele and epidermis. Knock-down of HvHKT1;1 in barley led to higher Na+ accumulation in both roots and leaves, while overexpression of HvHKT1;1 in salt-sensitive Arabidopsis hkt1-4 and sos1-12 loss-of-function lines resulted in significantly less shoot and root Na+ accumulation. Additionally, microelectrode ion flux measurements and root elongation assay revealed that the transgenic Arabidopsis plants exhibited a remarkable capacity for regulation of Na+, K+, Ca2+ and H+ homeostasis under salt stress. These results indicate that HvHKT1;1 is critical in radial root Na+ transport, which eventually reduces shoot Na+ accumulation. Additionally, HvHKT1;1 may be indirectly involved in retention of K+ and Ca2+ in root cells, which also improves plant salt tolerance. [ABSTRACT FROM AUTHOR]

Over 17 million km² of land is affected by soil flooding every year, resulting in substantial yield losses and jeopardizing food security across the globe. A key step in resolving this problem and creating stress-tolerant cultivars is an understanding of the mechanisms by which plants sense low-oxygen stress. In this work, we review the current knowledge about the oxygen-sensing and signaling pathway in mammalian and plant systems and postulate the potential role of ion channels as putative oxygen sensors in plant roots. We first discuss the definition and requirements for the oxygen sensor and the difference between sensing and signaling. We then summarize the literature and identify several known candidates for oxygen sensing in the mammalian literature. This includes transient receptor potential (TRP) channels; K+-permeable channels (Kv, BK and TASK); Ca2+ channels (RyR and TPC); and various chemo- and reactive oxygen species (ROS)-dependent oxygen sensors. Identified key oxygen-sensing domains (PAS, GCS, GAF and PHD) in mammalian systems are used to predict the potential plant counterparts in Arabidopsis. Finally, the sequences of known mammalian ion channels with reported roles in oxygen sensing were employed to BLAST the Arabidopsis genome for the candidate genes. Several plasma membrane and tonoplast ion channels (such as TPC, AKT and KCO) and oxygen domain-containing proteins with predicted oxygen-sensing ability were identified and discussed. We propose a testable model for potential roles of ion channels in plant hypoxia sensing. [ABSTRACT FROM AUTHOR]

Regulation of root cell K+ is essential for acclimation to low oxygen stress. The potential roles of GORK (depolarization- activated guard cell outward-rectifying potassium) channels and RBOHD (respiratory burst oxidase homologue D) in plant adaptive responses to hypoxia were investigated in the context of tissue specificity (epidermis versus stele; elongation versus mature zone) in roots of Arabidopsis. The expression of GORK and RBOHD was down-regulated by 2- to 3-fold within 1 h and 24 h of hypoxia treatment in Arabidopsis wild-type (WT) roots. Interestingly, a loss of the functional GORK channel resulted in a waterlogging-tolerant phenotype, while rbohD knockout was sensitive to waterlogging. To understand their functions under hypoxia stress, we studied K+, Ca2+, and reactive oxygen species (ROS) distribution in various root cell types. gork1-1 plants had better K+ retention ability in both the elongation and mature zone compared with the WT and rbohD under hypoxia. Hypoxia induced a Ca2+ increase in each cell type after 72 h, and the increase was much less pronounced in rbohD than in the WT. In most tissues except the elongation zone in rbohD, the H2O2 concentration had decreased after 1 h of hypoxia, but then increased significantly after 24 h of hypoxia in each zone and tissue, further suggesting that RBOHD may shape hypoxia-specific Ca2+ signatures via the modulation of apoplastic H2O2 production. Taken together, our data suggest that plants lacking functional GORK channels are more capable of retaining K+ for their better performance under hypoxia, and that RBOHD is crucial in hypoxia-induced Ca2+ signalling for stress sensing and acclimation mechanism. [ABSTRACT FROM AUTHOR]

In this article, we propose a new statistical method-MutRSeq-for detecting differentially expressed single nucleotide variants (SNVs) based on RNA-seq data. Specifically, we focus on nonsynonymous mutations and employ a hierarchical likelihood approach to jointly model observed mutation events as well as read count measurements from RNA-seq experiments. We then introduce a likelihood ratio-based test statistic, which detects changes not only in overall expression levels, but also in allele-specific expression patterns. In addition, this method can jointly test multiple mutations in one gene/pathway. The simulation studies suggest that the proposed method achieves better power than a few competitors under a range of different settings. In the end, we apply this method to a breast cancer data set and identify genes with nonsynonymous mutations differentially expressed between the triple negative breast cancer tumors and other subtypes of breast cancer tumors. [ABSTRACT FROM AUTHOR]

Background The anti-tumor activity of nab -paclitaxel followed by epirubicin/cyclophosphamide (EC) as neoadjuvant chemotherapy (NAC) in Asian patients remain unclear, particularly in the aggressive subtype triple-negative breast cancer (TNBC). This study aimed to evaluate the efficacy and safety of this NAC regimen in TNBC. Methods In this Simon's two-stage, phase II study, treatment-naïve patients with unilateral primary invasive TNBC were enrolled. Eligible patients received nab -paclitaxel 125 mg/m2 weekly on day 1 for 12 weeks, followed by dose-dense EC (epirubicin 90 mg/m2; cyclophosphamide 600 mg/m2) on day 1 for four 2-week cycles. The primary endpoint was the total pathological complete response (tpCR, ypT0/is ypN0) rate. Results A total of 55 eligible patients were enrolled and treated. After NAC, tpCR and breast pathological complete response were respectively observed in 43.1% (95% CI, 29.3-57.8) and 49.0% (95% CI, 34.8-63.4) of 51 evaluable patients for pathological response evaluation. 44 had an objective response as their best response (80.0%; 95% CI, 67.0-89.6). No correlations between clinicopathological variables and pathological/clinical response were observed. Grade 3 or more adverse events (AEs) occurred in 63.6% of 55 patients. The most frequent AEs were alopecia. No treatment-related surgical delay or death occurred. Conclusion Nab -paclitaxel followed by dose-dense EC as NAC demonstrates promising anti-tumor activity and acceptable tolerability for patients with TNBC. (ClinicalTrials.gov Identifier: NCT03799679). [ABSTRACT FROM AUTHOR]

Background. The frequency with which targeted tumor sequencing results will lead to implemented change in care is unclear. Prospective assessment of the feasibility and limitations of using genomic sequencing is critically important. Methods. A prospective clinical study was conducted on 100 patients with diverse-histology, rare, or poor-prognosis cancers to evaluate the clinical actionability of a Clinical Laboratory Improvement Amendments (CLIA)-certified, comprehensive genomic profiling assay (FoundationOne), using formalin-fixed, paraffin-embedded tumors. The primary objectives were to assess utility, feasibility, and limitations of genomic sequencing for genomically guided therapy or other clinical purpose in the setting of a multidisciplinary molecular tumor board. Results. Of the tumors from the 92 patients with sufficient tissue, 88 (96%) had at least onegenomic alteration (average 3.6, range 0-10). Commonly altered pathways included p53 (46%), RAS/RAF/MAPK (rat sarcoma; rapidly accelerated fibrosarcoma; mitogen-activated protein kinase) (45%), receptor tyrosine kinases/ligand (44%), PI3K/AKT/mTOR (phosphatidylinositol- 4,5-bisphosphate 3-kinase; protein kinase B; mammalian target of rapamycin) (35%), transcription factors/regulators (31%), and cell cycle regulators (30%). Many low frequency but potentially actionable alterations were identified in diverse histologies. Use of comprehensive profiling led to implementable clinical action in 35% of tumors with genomic alterations, including genomically guided therapy, diagnostic modification, and trigger for germline genetic testing. Conclusion. Use of targeted next-generation sequencing in the setting of an institutional molecular tumor board led to implementable clinical action in more than one third of patients with rare and poor-prognosis cancers. Major barriers to implementation of genomically guided therapy wereclinical status of the patient and drug access. Early and serial sequencing in the clinical course and expanded access to genomically guided early-phase clinical trials and targeted agents may increase actionability. [ABSTRACT FROM AUTHOR]

The next-generation sequencing data, called high-throughput sequencing data, are recorded as count data, which are generally far from normal distribution. Under the assumption that the count data follow the Poisson [ABSTRACT FROM AUTHOR]

Waterlogging is a major abiotic stress that limits the growth of plants. The crucial role of Ca2+ as a second messenger in response to abiotic and biotic stimuli has been widely recognized in plants. However, the physiological and molecular mechanisms of Ca2+ distribution within specific cell types in different root zones under hypoxia is poorly understood. In this work, whole-plant physiological and tissue-specific Ca2+ changes were studied using several ACA (Ca2+-ATPase) and CAX (Ca2+/proton exchanger) knock-out Arabidopsis mutants subjected to waterlogging treatment. In the wild-type (WT) plants, several days of hypoxia decreased the expression of ACA8, CAX4, and CAX11 by 33% and 50% compared with the control. The hypoxic treatment also resulted in an up to 11-fold tissue-dependent increase in Ca2+ accumulation in root tissues as revealed by confocal microscopy. The increase was much higher in stelar cells in the mature zone of Arabidopsis mutants with loss of function for ACA8, ACA11, CAX4, and CAX11. In addition, a significantly increased Ca2+ concentration was found in the cytosol of stelar cells in the mature zone after hypoxic treatment. Three weeks of waterlogging resulted in dramatic loss of shoot biomass in cax11 plants (67% loss in shoot dry weight), while in the WT and other transport mutants this decline was only 14-22%. These results were also consistent with a decline in leaf chlorophyll fluorescence (Fv/Fm). It is suggested that CAX11 plays a key role in maintaining cytosolic Ca2+ homeostasis and/or signalling in root cells under hypoxic conditions. [ABSTRACT FROM AUTHOR]

Background. Incidence rates of breast cancer continue to rise in the People's Republic of China. The purpose of this study was to describe Chinese trends in radical surgical modalities and influential imaging and demographic factors for breast malignancies. Materials and Methods. This study was a hospital-based, multicenter, 10-year (1999-2008), retrospective study. Descriptive statistical tests were used to illustrate information regarding radical surgical trends for the treatment of breast malignancies. Chi-square tests were used to assess effect of demographic factors in addition to imaging and pathological data on the specific surgical method. Results. A total of 4,211 patients were enrolled in the survey. Among them, 3,335 patients with stage 0 to stage III disease undergoing mastectomy or breast-conserving surgery (BCS) were included in the final analysis. The rate of BCS increased from 1.53% in 1999 to 11.88% in 2008. The rate of mastectomy declined over this time period, from 98.47% in 1999 to 88.12% in 2008, with increasing use of diagnostic imaging methods and pathological biopsies. A significantly greater percentage of patients with office work, high education levels, unmarried status, younger age, and early pathological stages preferred BCS compared with mastectomy. Conclusion. Rates of mastectomy in China remain elevated due to diagnosis at higher stages; however, because of increased use of diagnostic imaging, improvement of biopsy methods, and patient education, rates of less invasive lumpectomy are increasing and rates of mastectomy have decreased in China. [ABSTRACT FROM AUTHOR]

Background and Objective. Incidence of and mortality rates for breast cancer continue to rise in the People's Republic of China. The purpose of this study was to analyze differences in characteristics of breast malignancies between China and the U.S. Methods. Data from 384,262 breast cancer patients registered in the U.S. Surveillance, Epidemiology, and End Results (SEER) program from 2000 to 2010 were compared with 4,211 Chinese breast cancer patients registered in a Chinese database from 1999 to 2008. Outcomes included age, race, histology, tumor and node staging, laterality, surgical treatment method, and reconstruction. The Pearson chi-square and Fisher's exact tests were used to compare rates. Results. Infiltrating ductal carcinoma was the most common type of malignancy in the U.S. and China. The mean number of positive lymph nodes was higher in China (2.59 vs. 1.31, p < .001). Stage at diagnosis was higher in China (stage IIA vs. I, p < .001). Mean size of tumor at diagnosis was higher in China (32.63 vs. 21.57 mm). Mean age at diagnosis was lower in China (48.28 vs. 61.29 years, p < .001). Moreover, 2.0% of U.S. women underwent radical mastectomy compared with 12.5% in China, and 0.02% in China underwent reconstructive surgery. Conclusion. Chinese women were diagnosed at younger ages with higher stage and larger tumors and underwent more aggressive surgical treatment. Prospective trials should be conducted to address screening, surgical, and tumor discrepancies between China and the U.S. [ABSTRACT FROM AUTHOR]

A thorough understanding of ionic detoxification and homeostasis is imperative for improvement of salt tolerance in crops. However, the homeostasis of elements and their relationship to metabolites under salt stress have not been fully elucidated in plants. In this study, Tibetan wild barley accessions, XZ16 and XZ169, differing in salt tolerance, and a salt-tolerant cultivar CM72 were used to investigate ionomic profile changes in tissues in response to 150 and 300 mM NaCl at the germination and seedling stages. At the germination stage, the contents of Ca and Fe significantly decreased in roots, while K and S contents increased, and Ca and Mg contents decreased in shoots, after 10 d of treatment. At the seedling stage, the contents of K, Mg, P and Mn in roots and of K, Ca, Mg and S in shoots decreased significantly after 21 d of treatment. Moreover, Na had a significant negative correlation with metabolites involved in glycolysis, α-ketoglutaric acid, maleic acid and alanine in roots, and metabolites associated with the tricarboxylic acid (TCA) cycle, sucrose, polyols and aspartate in leaves. The salt-tolerant genotypes XZ16 and CM72 showed a lower Na content in tissues, and less reduction in Zn and Cu in roots, of Ca, Mg and S in leaves, and shoot DW than the sensitive genotype XZ169, when exposed to a higher salt level. The results indicated that restriction of Na accumulation and rearrangement of nutrient elements and metabolites in barley tissues are possibly attributable to development of salt tolerance. [ABSTRACT FROM PUBLISHER]

The discovery of the START family of abscisic acid (ABA) receptors places these proteins at the front of a protein kinase/phosphatase signal cascade that promotes stomatal closure. The connection of these receptors to Ca2+ signals evoked by ABA has proven more difficult to resolve, although it has been implicated by studies of the pyrbactin-insensitive pyr1/pyl1/pyl2/pyl4 quadruple mutant. One difficulty is that flux through plasma membrane Ca2+ channels and Ca2+ release from endomembrane stores coordinately elevate cytosolic free Ca2+ concentration ([Ca2+]i) in guard cells, and both processes are facilitated by ABA. Here, we describe a method for recording Ca2+ channels at the plasma membrane of intact guard cells of Arabidopsis (Arabidopsis thaliana). We have used this method to resolve the loss of ABA-evoked Ca2+ channel activity at the plasma membrane in the pyr1/pyl1/pyl2/pyl4 mutant and show the consequent suppression of [Ca2+]i increases in vivo. The basal activity of Ca2+ channels was not affected in the mutant; raising the concentration of Ca2+ outside was sufficient to promote Ca2+ entry, to inactivate current carried by inward-rectifying K+ channels and to activate current carried by the anion channels, both of which are sensitive to [Ca2+]i elevations. However, the ABA-dependent increase in reactive oxygen species (ROS) was impaired. Adding the ROS hydrogen peroxide was sufficient to activate the Ca2+ channels and trigger stomatal closure in the mutant. These results offer direct evidence of PYR/PYL/RCAR receptor coupling to the activation by ABA of plasma membrane Ca2+ channels through ROS, thus affecting [Ca2+]i and its regulation of stomatal closure. [ABSTRACT FROM AUTHOR]

Endothelial cells (ECs) are critical for angiogenesis, and microRNAs play important roles in this process. We investigated the regulatory role of microRNAs in ECs of hepatocellular carcinoma (HCC) by examining the microRNA expression profile of human umbilical vein endothelial cells (HUVECs) in the absence or presence of human HCC cells, and identified miR-146a as the most highly upregulated microRNA. Furthermore, we revealed that miR-146a promoted the expression of platelet-derived growth factor receptor α (PDGFRA) in HUVECs, and this process was mediated by BRCA1. Overexpression of PDGFRA in the ECs of HCC tissues was associated with microvascular invasion and predicted a poorer prognosis. These results suggest that miR-146a plays a key role in regulating the angiogenic activity of ECs in HCC through miR-146a–BRCA1–PDGFRA pathway. MiR-146a and PDGFRA may emerge as potential anti-angiogenic targets on ECs for HCC therapy. [ABSTRACT FROM AUTHOR]

Tibetans live on the highest plateau in the world, their current population size is approximately 5 million, and most of them live at an altitude exceeding 3,500 m. Therefore, the Tibetan Plateau is a remarkable area for cultural and biological studies of human population history. However, the chronological profile of the Tibetan Plateau’s colonization remains an unsolved question of human prehistory. To reconstruct the prehistoric colonization and demographic history of modern humans on the Tibetan Plateau, we systematically sampled 6,109 Tibetan individuals from 41 geographic populations across the entire region of the Tibetan Plateau and analyzed the phylogeographic patterns of both paternal (n = 2,354) and maternal (n = 6,109) lineages as well as genome-wide single nucleotide polymorphism markers (n = 50) in Tibetan populations. We found that there have been two distinct, major prehistoric migrations of modern humans into the Tibetan Plateau. The first migration was marked by ancient Tibetan genetic signatures dated to approximately 30,000 years ago, indicating that the initial peopling of the Tibetan Plateau by modern humans occurred during the Upper Paleolithic rather than Neolithic. We also found evidences for relatively young (only 7–10 thousand years old) shared Y chromosome and mitochondrial DNA haplotypes between Tibetans and Han Chinese, suggesting a second wave of migration during the early Neolithic. Collectively, the genetic data indicate that Tibetans have been adapted to a high altitude environment since initial colonization of the Tibetan Plateau in the early Upper Paleolithic, before the last glacial maximum, followed by a rapid population expansion that coincided with the establishment of farming and yak pastoralism on the Plateau in the early Neolithic. [ABSTRACT FROM PUBLISHER]

Halophyte species implement a "salt-including" strategy, sequestering significant amounts of Na+ to cell vacuoles. This requires a reduction of passive Na+ leak from the vacuole. In this work, we used quinoa (Chenopodium quinoa) to investigate the ability of halophytes to regulate Na+-permeable slow-activating (SV) and fast-activating (FV) tonoplast channels, linking it with Na+ accumulation in mesophyll cells and salt bladders as well as leaf photosynthetic efficiency under salt stress. Our data indicate that young leaves rely on Na+ exclusion to salt bladders, whereas old ones, possessing far fewer salt bladders, depend almost exclusively on Na+ sequestration to mesophyll vacuoles. Moreover, although old leaves accumulate more Na+, this does not compromise their leaf photochemistry. FV and SV channels are slightly more permeable for K+ than for Na+, and vacuoles in young leaves express less FV current and with a density unchanged in plants subjected to high (400 HIM NaCl) salinity. In old leaves, with an intrinsically lower density of the FV current, FV channel density decreases about 2-fold in plants grown under high salinity. In contrast, intrinsic activity of SV channels in vacuoles from young leaves is unchanged under salt stress. In vacuoles of old leaves, however, it is 2- and 7-fold lower in older compared with young leaves in control- and salt-grown plants, respectively. We conclude that the negative control of SV and FV tonoplast channel activity in old leaves reduces Na+ leak, thus enabling efficient sequestration of Na+ to their vacuoles. This enables optimal photosynthetic performance, conferring salinity tolerance in quinoa species. [ABSTRACT FROM AUTHOR]

The continued interest in protein engineering has led to intense efforts in developing novel stable enzymes, which could not only give boost to industrial and biomedical applications, but also enhance our understanding of the structure–function relationships of proteins. We present here the generation of three hybrid proteins of cytochrome c (cyt c) and peroxidase via structure-based rational mutagenesis of cyt c. Several residues (positions 67, 70, 71 and 80) in the distal heme region of cyt c were mutated to the highly conserved amino acids in the heme pocket of peroxidases. The multiple mutants were found to exhibit high peroxidase activity and conserve the impressive stability of cyt c. We expect that this strategy could be extended to other cases of metalloprotein engineering, and lead to the development of stable and active biocatalysts for industrial uses. Besides, this study also provides insight into the structure–function relationships of hemoproteins. [ABSTRACT FROM PUBLISHER]

Large-scale genome-wide association studies (GWAS) have identified over 40 genomic regions significantly associated with type 2 diabetes mellitus. However, GWAS results are not always straightforward to interpret, and linking these loci to meaningful disease etiology is often difficult without extensive follow-up studies. The authors expanded on previously reported type 2 diabetes mellitus GWAS from the nested case-control studies of 2 prospective US cohorts by incorporating expression single nucleotide polymorphism (SNP) information and applying SNP set enrichment analysis to identify sets of SNPs associated with genes that could provide further biologic insight to traditional genome-wide analysis. Using data collected between 1989 and 1994 in these previous studies to form a nested case-control study, the authors found that 3 of the most significantly associated SNPs to type 2 diabetes mellitus in their study are expression SNPs to the lymphocyte antigen 75 gene (LY75), the ubiquitin-specific peptidase 36 gene (USP36), and the phosphatidylinositol transfer protein, cytoplasmic 1 gene (PITPNC1). SNP set enrichment analysis of the GWAS results identified enrichment for expression SNPs to the macrophage-enriched module and the Gene Ontology (GO) biologic process fat cell differentiation human, which includes the transcription factor 7-like 2 gene (TCF7L2), as well as other type 2 diabetes mellitus-associated genes. Integrating genome-wide association, gene expression, and gene set analysis may provide valuable biologic support for potential type 2 diabetes mellitus susceptibility loci and may be useful in identifying new targets or pathways of interest for the treatment and prevention of type 2 diabetes mellitus. [ABSTRACT FROM AUTHOR]

The dynamics of stomatal movements and their consequences for photosynthesis and transpirational water loss have long been incorporated into mathematical models, but none have been developed from the bottom up that are widely applicable in predicting stomatal behavior at a cellular level. We previously established a systems dynamic model incorporating explicitly the wealth of biophysical and kinetic knowledge available for guard cell transport, signaling, and homeostasis. Here we describe the behavior of the model in response to experimentally documented changes in primary pump activities and malate (Mal) synthesis imposed over a diurnal cycle. We show that the model successfully recapitulates the cyclic variations in H+, K+, Cl-, and Mal concentrations in the cytosol and vacuole known for guard cells. It also yields a number of unexpected and counterintuitive outputs. Among these, we report a diurnal elevation in cytosolic-free Ca2+ concentration and an exchange of vacuolar Cl- with Mai, both of which find substantiation in the literature but had previously been suggested to require additional and complex levels of regulation. These findings highlight the true predictive power of the OnGuard model in providing a framework for systems analysis of stomatal guard cells, and they demonstrate the utility of the OnGuard software and HoTSig library in exploring fundamental problems in cellular physiology and homeostasis. [ABSTRACT FROM AUTHOR]

Stomatal guard cells play a key role in gas exchange for photosynthesis while minimizing transpirational water loss from plants by opening and closing the stomatal pore. Foliar gas exchange has long been incorporated into mathematical models, several of which are robust enough to recapitulate transpirational characteristics at the whole-plant and community levels. Few models of stomata have been developed from the bottom up, however, and none are sufficiently generalized to be widely applicable in predicting stomatal behavior at a cellular level. We describe here the construction of computational models for the guard cell, building on the wealth of biophysical and kinetic knowledge available for guard cell transport, signaling, and homeostasis. The OnGuard software was constructed with the HoTSig library to incorporate explicitly all of the fundamental properties for transporters at the plasma membrane and tonoplast, the salient features of osmolite metabolism, and the major controls of cytosolic-free Ca2+ concentration and pH. The library engenders a structured approach to tier and interrelate computational elements, and the OnGuard software allows ready access to parameters and equations 'on the fly' while enabling the network of components within each model to interact computationally. We show that an OnGuard model readily achieves stability in a set of physiologically sensible baseline or Reference States; we also show the robustness of these Reference States in adjusting to changes in environmental parameters and the activities of major groups of transporters both at the tonoplast and plasma membrane. The following article addresses the predictive power of the OnGuard model to generate unexpected and counterintuitive outputs. [ABSTRACT FROM AUTHOR]

Microalgal photo-biocatalysis is a green technique for asymmetric synthesis. Asymmetric reduction of nonnatural prochiral ketones to produce chiral alcohols by microalgal photo-biocatalysis was studied in this work. Acetophenone (ACP) and ethyl acetoacetate (EAA) were chosen as model substrates for aromatic ketones and β-ketoesters, respectively. Two prokaryotic cyanophyta and two eukaryotic chlorophyta were selected as photo-biocatalysts. The results proved that nonnatural prochiral ketones can be reduced by microalgal photo-biocatalysis with high enantioselectivity. Illumination is indispensable to the photo-biocatalysis. For aromatic ketone, cyanophyta are eligible biocatalysts. For ACP asymmetric reduction reaction, about 45% yield and 97% e.e. can be achieved by the photo-biocatalysis reaction with Spirulina platensis as biocatalyst. On the contrary, chlorophyta are efficient biocatalysts for β-ketoester asymmetric reduction reaction among the four tested algae. For EAA asymmetric reduction reaction, about 70% yield and 90% e.e. can be achieved with Scenedesmus obliquus as biocatalyst. The microalgae used in this study outperformed other characterized biocatalysts such as microbial and plant cells. [ABSTRACT FROM AUTHOR]