Screening of environmental stimuli for the positive regulation of stomatal aperture in centipedegrass.

Grasslands, the largest carbon pool in China, possess enormous potential for carbon sequestration. Increasing the stomatal aperture to increase the CO2 absorption capacity is a potential method to improve plant photosynthetic efficiency and ultimately enhance the carbon sequestration capacity of grass plants. Research on stomatal aperture regulation has focused mostly on Arabidopsis or crops, while research on grass plants in these areas is scarce, which seriously restricts the implementation of this grassland carbon sequestration strategy. Here, a widely used ecological grass, centipedegrass, was used as the experimental material. First, a convenient method for observing the stomatal aperture was developed. The leaves were floated in a potassium ion-containing open solution (67 mM KCl, pH 6.0) with the adaxial surface rather than the abaxial surface in contact with the solution and were cultivated under light for 1.5 h. Then, nail polish was applied on the adaxial surface, and a large number of open stomata were imprinted. Second, with the help of this improved method, the concentration‒response characteristics of the stomatal aperture to eleven environmental stimuli were tested. The stomatal aperture is dependent on these environmental stimuli in a concentration-dependent manner. The addition of 100 µM brassinolide led to the maximal stomatal aperture. This study provided a technical basis for manipulating stomatal opening to increase the carbon sequestration capacity of centipedegrass.

Identification of Clubroot (Plasmodiophora brassicae) Resistance Loci in Chinese Cabbage (Brassica rapa ssp. pekinensis) with Recessive Character.

The soil-borne pathogen Plasmodiophora brassicae is the causal agent of clubroot, a major disease in Chinese cabbage (Brassica rapa ssp. pekinensis). The host's resistance genes often confer immunity to only specific pathotypes and may be rapidly overcome. Identification of novel clubroot resistance (CR) from germplasm sources is necessary. In this study, Bap246 was tested by being crossed with different highly susceptible B. rapa materials and showed recessive resistance to clubroot. An F2 population derived from Bap246 × Bac1344 was used to locate the resistance Quantitative Trait Loci (QTL) by Bulk Segregant Analysis Sequencing (BSA-Seq) and QTL mapping methods. Two QTL on chromosomes A01 (4.67-6.06 Mb) and A08 (10.42-11.43 Mb) were found and named Cr4Ba1.1 and Cr4Ba8.1, respectively. Fifteen and eleven SNP/InDel markers were used to narrow the target regions in the larger F2 population to 4.67-5.17 Mb (A01) and 10.70-10.84 Mb (A08), with 85 and 19 candidate genes, respectively. The phenotypic variation explained (PVE) of the two QTL were 30.97% and 8.65%, respectively. Combined with gene annotation, mutation site analysis, and real-time quantitative polymerase chain reaction (qRT-PCR) analysis, one candidate gene in A08 was identified, namely Bra020861. And an insertion and deletion (InDel) marker (co-segregated) named Crr1-196 was developed based on the gene sequence. Bra013275, Bra013299, Bra013336, Bra013339, Bra013341, and Bra013357 in A01 were the candidate genes that may confer clubroot resistance in Chinese cabbage. The resistance resource and the developed marker will be helpful in Brassica breeding programs.

Highly Selective and Portable Fluorescence Turn-On Detection of Sc3+ in Ore and Water Based on Strong Lewis Acid-Base Coordination.

Detecting scandium (Sc) with high selectivity and sensitivity is a challenging task due to its chemical similarity to other rare earth ions. Our findings show that the fluorescence of the complex fluorescent indicator calcein (CL) is quenched under acidic conditions (pH = 2), and Sc3+ strongly inhibits this process. The results demonstrate that CL forms multimers and precipitates out of the solution under acidic conditions, while Sc3+ causes a significant decrease in the scattering intensity of the solution. Additional experiments revealed that the strong Lewis acid nature of Sc3+ complexes with the carboxyl groups of CL leads to increased dispersion of CL even under acidic conditions, thus enhancing its absorption and fluorescence. The complexation ratio of Sc3+ and CL was investigated through spectral titrations and theoretical calculations. The interaction between Sc3+ and CL is the strongest among rare earth and common metal ions due to the smallest ionic radius, resulting in high selectivity. The fluorescence turn-on strategy had a linear range of 0.04 to 2.25 µM under optimal conditions, with a detection limit of 20 nM for Sc3+. The combination of 3D printing and a smartphone program allows for portable on-site analysis of Sc3+. Mineral and water samples were used to demonstrate the potential of this strategy for the rapid, selective, and sensitive analysis of low levels of Sc3+.

Role of Microbes in Alleviating Crop Drought Stress: A Review.

Drought stress is an annual global phenomenon that has devastating effects on crop production, so numerous studies have been conducted to improve crop drought resistance. Plant-associated microbiota play a crucial role in crop health and growth; however, we have a limited understanding of the key processes involved in microbiome-induced crop adaptation to drought stress. In this review, we summarize the adverse effects of drought stress on crop growth in terms of germination, photosynthesis, nutrient uptake, biomass, and yield, with a focus on the response of soil microbial communities to drought stress and plant-microbe interactions under drought stress. Moreover, we review the morpho-physiological, biochemical, and molecular mechanisms underlying the mitigation effect of microbes on crop drought stress. Finally, we highlight future research directions, including the characterization of specific rhizosphere microbiome species with corresponding root exudates and the efficiency of rhizobacteria inoculants under drought conditions. Such research will advance our understanding of the complex interactions between crops and microbes and improve crop resistance to drought stress through the application of beneficial drought-adaptive microbes.

Changes in microbial composition and interaction patterns of female urogenital tract and rectum in response to HPV infection.

BACKGROUND: Previous studies have shown that changes in the microbial community of the female urogenital tract are associated with Human papillomavirus (HPV) infection. However, research on this association was mostly focused on a single site, and there are currently few joint studies on HPV infection and multiple sites in the female urogenital tract. METHODS: We selected 102 healthy women from Yunnan Province as the research object, collected cervical exfoliation fluid, vaginal, urethral, and rectal swabs for microbial community analysis, and measured bacterial load, and related cytokine content. The link between HPV, microbiota, and inflammation was comprehensively evaluated using bioinformatics methods. FINDINGS: The impact of HPV infection on the microbial composition of different parts varies. We have identified several signature bacterial genera that respond to HPV infection in several detection sites, such as Corynebacterium, Lactobacillus, Campylobacter, and Cutibacterium have been detected in multiple sites, reflecting their potential significance in cross body sites HPV infection responses. There was a solid microbial interaction network between the cervix, vagina, and urethra. The interrelationships between inflammatory factors and different bacterial genera might also affect the immune system's response to HPV infection. INTERPRETATION: It might be an effective strategy to prevent and treat HPV infection by simultaneously understanding the correlation between the microbial changes in multiple parts of the female urogenital tract and rectum and HPV infection, and controlling the microbial network related to HPV infection in different parts.

Portable and Rapid Fluorescence Turn-On Detection of Total Pepsin in Saliva Based on Strong Electrostatic Interactions.

Salivary pepsin has been proposed as a promising diagnostic marker for gastroesophageal reflux disease (GERD). However, the activity of human pepsin is strongly influenced by pH, and the acidic condition (pH ∼ 2) is optimal, which is a contradiction for the pepsin detection kit based on its catalytic activity. Thus, its accurate quantification in saliva (neutral pH) by readily rapid tools with simplicity and low cost is still challenging. Herein, a convenient fluorescence assay has been developed for the rapid detection of pepsin at neutral pH based on its electrostatic interaction with SYBR Green (SG) rather than the bioactivity. At neutral pH, the positively charged SG fluorophore can be effectively adsorbed by the negatively charged pepsin due to the low isoelectric point (pI) and large molecular size of pepsin. Thus, the molecular rotation of SG is limited, and its fluorescence intensity is significantly increased. The strategy was further confirmed to have the same fluorescence response as that of normally active and inactivated pepsin. Due to the unique pI of pepsin, the fluorescence strategy is highly selective for pepsin compared to other proteins. On the basis of this strategy, a smartphone-based fluorescence capture device integrated with a programmed Python program was fabricated for both color recognition and the accurate detection of pepsin within 3 min. Under the optimal conditions, this turn-on sensor allowed for the on-site analysis of pepsin with a detection limit of 0.2 µg/mL. Moreover, this strategy was successfully used to assess salivary pepsin to aid in the noninvasive diagnosis of GERD.

Pose-invariant and occlusion-robust neonatal facial pain assessment.

Neonatal Facial Pain Assessment (NFPA) is essential to improve neonatal pain management. Pose variation and occlusion, which can significantly alter the facial appearance, are two major and still unstudied barriers to NFPA. We bridge this gap in terms of method and dataset. Techniques to tackle both challenges in other tasks either expect pose/occlusion-invariant deep learning methods or first generate a normal version of the input image before feature extraction, combining these we argue that it is more effective to jointly perform adversarial learning and end-to-end classification for their mutual benefit. To this end, we propose a Pose-invariant Occlusion-robust Pain Assessment (POPA) framework, with two novelties. We incorporate adversarial learning-based disturbance mitigation for end-to-end pain-level classification and propose a novel composite loss function for facial representation learning; compared to the vanilla discriminator that implicitly determines occlusion and pose conditions, we propose a multi-scale discriminator that determines explicitly, while incorporating local discriminators to enhance the discrimination of key regions. For a comprehensive evaluation, we built the first neonatal pain dataset with disturbance annotation involving 1091 neonates and also applied the proposed POPA to the facial expression recognition task. Extensive qualitative and quantitative experiments prove the superiority of the POPA.

Construction and validation of a predictive risk model for nosocomial infections with MDRO in NICUs: a multicenter observational study.

Objectives: This study aimed to construct and validate a predictive risk model (PRM) for nosocomial infections with multi-drug resistant organism (MDRO) in neonatal intensive care units (NICUs), in order to provide a scientific and reliable prediction tool, and to provide reference for clinical prevention and control of MDRO infections in NICUs. Methods: This multicenter observational study was conducted at NICUs of two tertiary children's hospitals in Hangzhou, Zhejiang Province. Using cluster sampling, eligible neonates admitted to NICUs of research hospitals from January 2018 to December 2020 (modeling group) or from July 2021 to June 2022 (validation group) were included in this study. Univariate analysis and binary logistic regression analysis were used to construct the PRM. H-L tests, calibration curves, ROC curves and decision curve analysis were used to validate the PRM. Results: Four hundred and thirty-five and one hundred fourteen neonates were enrolled in the modeling group and validation group, including 89 and 17 neonates infected with MDRO, respectively. Four independent risk factors were obtained and the PRM was constructed, namely: P = 1/ (1+ e-X), X = -4.126 + 1.089× (low birth weight) +1.435× (maternal age ≥ 35 years) +1.498× (use of antibiotics >7 days) + 0.790× (MDRO colonization). A nomogram was drawn to visualize the PRM. Through internal and external validation, the PRM had good fitting degree, calibration, discrimination and certain clinical validity. The prediction accuracy of the PRM was 77.19%. Conclusion: Prevention and control strategies for each independent risk factor can be developed in NICUs. Moreover, clinical staff can use the PRM to early identification of neonates at high risk, and do targeted prevention to reduce MDRO infections in NICUs.

T cell infiltration into the brain triggers pulmonary dysfunction in murine Cryptococcus-associated IRIS.

Cryptococcus-associated immune reconstitution inflammatory syndrome (C-IRIS) is a condition frequently occurring in immunocompromised patients receiving antiretroviral therapy. C-IRIS patients exhibit many critical symptoms, including pulmonary distress, potentially complicating the progression and recovery from this condition. Here, utilizing our previously established mouse model of unmasking C-IRIS (CnH99 preinfection and adoptive transfer of CD4+ T cells), we demonstrated that pulmonary dysfunction associated with the C-IRIS condition in mice could be attributed to the infiltration of CD4+ T cells into the brain via the CCL8-CCR5 axis, which triggers the nucleus tractus solitarius (NTS) neuronal damage and neuronal disconnection via upregulated ephrin B3 and semaphorin 6B in CD4+ T cells. Our findings provide unique insight into the mechanism behind pulmonary dysfunction in C-IRIS and nominate potential therapeutic targets for treatment.

Estrogen receptor alpha signaling in dendritic cells modulates autoimmune disease phenotype in mice.

Estrogen is a disease-modifying factor in multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE) via estrogen receptor alpha (ERα). However, the mechanisms by which ERα signaling contributes to changes in disease pathogenesis have not been completely elucidated. Here, we demonstrate that ERα deletion in dendritic cells (DCs) of mice induces severe neurodegeneration in the central nervous system in a mouse EAE model and resistance to interferon beta (IFNß), a first-line MS treatment. Estrogen synthesized by extragonadal sources is crucial for controlling disease phenotypes. Mechanistically, activated ERα directly interacts with TRAF3, a TLR4 downstream signaling molecule, to degrade TRAF3 via ubiquitination, resulting in reduced IRF3 nuclear translocation and transcription of membrane lymphotoxin (mLT) and IFNß components. Diminished ERα signaling in DCs generates neurotoxic effector CD4+ T cells via mLT-lymphotoxin beta receptor (LTßR) signaling. Lymphotoxin beta receptor antagonist abolished EAE disease symptoms in the DC-specific ERα-deficient mice. These findings indicate that estrogen derived from extragonadal sources, such as lymph nodes, controls TRAF3-mediated cytokine production in DCs to modulate the EAE disease phenotype.

Accuracy of Intraocular Lens Power Calculation Formulas in Patients With Multifocal Intraocular Lens Implantation With Optic Capture in Berger Space for Pediatric Cataract.

PURPOSE: To assess the accuracy of intraocular lens (IOL) calculation formulas in pediatric patients with multifocal IOL implantation with optic capture in Berger space. METHODS: This prospective observational study enrolled 68 children (101 eyes), aged 3 to 14 years, who received multifocal IOL (Tecnis ZMB00; Abbott Medical Optics) implantation with optic capture in Berger space from June 2019 to June 2020 in Qingdao Eye Hospital. Ocular biometry was performed using the IOLMaster 700 (Carl Zeiss Meditec). The IOL power and intended postoperative refraction were calculated using the Hoffer Q, Barrett Universal II, Holladay, Holladay2, SRK/T, Haigis, and SRKII formulas. The refractive state of patients, prediction error, and absolute prediction error were evaluated. RESULTS: The mean absolute error of the formulas was significantly different (0.49 diopters [D], Hoffer Q; 0.52 D, Barrett Universal II; 0.47 D, Holladay; 0.54 D, Holladay2; 0.52 D, SRK/T; 0.67 D, Haigis; 0.99 D, SRKII; P < .001). However, the Hoffer Q, Barrett Universal II, Holladay, Holladay2, and SRK/T formulas had a similar accuracy in predicting refractive error within ±0.50 D (62.4%, 59.4%, 62.4%, 62.4%, and 58.4%). There was a trend toward a greater prediction error in eyes with a shorter axial length (≤ 22 mm) or a steeper cornea (> 43.50 D), for which the Hoffer Q and Holladay2 formulas were more accurate. When the axial length was greater than 22 mm or the corneal curvature was 43.50 D or less, the Holladay, Hoffer Q, and Barrett Universal II formulas were more accurate. CONCLUSIONS: For patients with pediatric cataract treated with multifocal IOL implantation with optic capture in Berger space, the Hoffer Q, Barrett Universal II, Holladay, Holladay2, and SRK/T formulas performed better than the other formulas. [J Pediatr Ophthalmol Strabismus. 2023;60(2):139-146.].

An appropriate ammonium: nitrate ratio promotes the growth of centipedegrass: insight from physiological and micromorphological analyses.

Reasonable nitrogen fertilizer application is an important strategy to maintain optimal growth of grasslands, thereby enabling them to better fulfil their ecological functions while reducing environmental pollution caused by high nitrogen fertilizer production and application. Optimizing the ammonium (NH4 +):nitrate (NO3 -) ratio is a common approach for growth promotion in crops and vegetables, but research on this topic in grass plants has not received sufficient attention. Centipedegrass, which is widely used in landscaping and ecological protection, was used as the experimental material. Different NH4 +:NO3 - ratios (0: 100, 25:75, 50:50, 75:25, 100:0) were used as the experimental treatments under hydroponic conditions. By monitoring the physiological and morphological changes under each treatment, the appropriate NH4 +:NO3 - ratio for growth and its underlying mechanism were determined. As the proportion of ammonium increased, the growth showed a "bell-shaped" response, with the maximum biomass and total carbon and nitrogen accumulation achieved with the NH4 +:NO3 - ratio of 50:50 treatment. Compared with the situation where nitrate was supplied alone, increasing the ammonium proportion increased the whole plant biomass by 93.2%, 139.7%, 59.0%, and 30.5%, the whole plant nitrogen accumulation by 44.9%, 94.6%, 32.8%, and 54.8%, and the whole plant carbon accumulation by 90.4%, 139.9%, 58.7%, and 26.6% in order. As a gateway for nitrogen input, the roots treated with an NH4 +:NO3 - ratio of 50:50 exhibited the highest ammonium and nitrate uptake rate, which may be related to the maximum total root length, root surface area, average root diameter, root volume, and largest root xylem vessel. As a gateway for carbon input, leaves treated with an NH4 +:NO3 - ratio of 50:50 exhibited the highest stomatal aperture, stomatal conductance, photosynthetic rate, transpiration rate, and photosynthetic products. The NH4 +:NO3 - ratio of 50:50 treatment had the largest stem xylem vessel area. This structure and force caused by transpiration may synergistically facilitate root-to-shoot nutrient translocation. Notably, the change in stomatal opening occurred in the early stage (4 hours) of the NH4 +:NO3 - ratio treatments, indicating that stomates are structures that are involved in the response to changes in the root NH4 +:NO3 - ratio. In summary, we recommend 50:50 as the appropriate NH4 +:NO3 - ratio for the growth of centipedegrass, which not only improves the nitrogen use efficiency but also enhances the carbon sequestration capacity.

Ten-Year Analysis of Pathogenic Factors and Etiological Characteristics of Endophthalmitis from a Tertiary Eye Center in North China.

Purpose: To describe the etiology and spectrum of isolated pathogens in endophthalmitis over 10 years from an ophthalmic hospital in North China and report their antimicrobial susceptibilities. Patients and Methods: The data covered the patients with endophthalmitis treated at Qingdao Eye Hospital from January 2011 to December 2020. Patients' medical history, pathogenic factors, bacterial and fungal culture results of intraocular specimens, and in vitro drug sensitivity test results were assessed. Results: A total of 524 cases were counted in this study. Exogenous endophthalmitis was the main component, accounting for 94.66%, of which 49.62% of eyes had a history of ophthalmic trauma, intraocular surgery in 26.72% and suppurative keratitis in 17.37%. By comparison, endogenous endophthalmitis was found in only 5.34% of eyes. Among the 292 strains of pathogenic organisms obtained by co-culture, gram-positive bacteria accounted for 64.04%, with Staphylococcus epidermidis as the predominant pathogen (29.45%). Gram-positive cocci were identified in 76.77% of eyes with traumatic endophthalmitis, while 53.70% of keratitis-associated endophthalmitis was caused by fungi. The high susceptibility of bacteria to vancomycin (77.78%~98.33%) supported its continued use as empirical treatment. Among the fluoroquinolones, gram-positive cocci showed a higher susceptibility to gatifloxacin (94.83%), while there was a significant decrease to levofloxacin (51.67%). Gram-negative bacteria were less sensitive to cephalosporins (45.95%~66.67%) than fluoroquinolones (68.42%~78.05%) and aminoglycosides (75.00%~78.05%). Fungal susceptibilities to voriconazole and amphotericin B were 90.16% and 70.31% respectively. More than half of the 11 antibiotics were observed to exhibit a trend of reduced susceptibility. Conclusion: Ophthalmic trauma was the primary pathogenic factor of endophthalmitis. Gram-positive cocci were the most common pathogens of traumatic and postoperative endophthalmitis, while suppurative keratitis-associated endophthalmitis often resulted from fungal pathogens. Levofloxacin as the preferred antibiotic in the perioperative period and cephalosporin as the first-line drug for the treatment of empiric endophthalmitis need to be vigilant.

Knowledge, Attitudes, and Practices of NICU Doctors and Nurses Toward Prevention and Control of Nosocomial Infection With Multidrug Resistant Organism.

Background: Nosocomial infection with multidrug resistant organisms (MDRO) can directly influence the curative effect and the prognosis of neonates, bringing great difficulties to clinical treatment. As direct contacts of neonates, the knowledge, attitudes, and practices (KAP) of doctors and nurses are critical for the prevention and control of MDRO infection in neonatal intensive care units (NICUs). Purpose: This study describes the KAP of doctors and nurses in NICUs toward the prevention and control of nosocomial infection with MDRO and analyzes its influencing factors. Methods: This cross-sectional study used convenience sampling to survey 397 doctors and nurses from the NICU of 28 hospitals in 11 cities in Zhejiang Province, China. A univariate analysis and a multiple linear regression were used to analyze the data. Results: The median scoring rate (interquartile range) of the knowledge, attitude, and practice questionnaire was 0.86 (0.82-0.91), 0.98 (0.91-1.00), and 0.995 (0.97-1.00), respectively. However, the median scoring rate regarding "basic knowledge of MDRO" and "special prevention and control measures" was 0.50 in knowledge. The multiple linear regression showed that the influencing factors of KAP were hospital grade, professional title, gender, regular supervision, and training. Conclusions: There was still room for improvement in the KAP of NICU doctors and nurses, especially regarding the knowledge. Men, doctors and nurses in Grade II hospitals, and doctors and nurses with primary professional titles had worse KAP. Training and supervision helped improve the KAP. Relevance to Clinical Practice: To improve the KAP of doctors and nurses to enhance the prevention and control effect for the MDRO infection in NICUs, hospitals and departments should carry out targeted training and strengthen supervision, while Grade II hospitals, men, and doctors and nurses with primary professional titles need more attention.

Effectiveness of Pedagogical Tools for Teaching Medical Gross Anatomy During the COVID-19 Pandemic.

Medical institutions have been forced to modify gross anatomy pedagogy to comply with the health restrictions imposed by the novel coronavirus (COVID-19). Boston University School of Medicine (BUSM) is one such institution that temporarily restructured its course. We replaced cadaveric dissection activities with prosections and placed a greater emphasis on a flipped classroom model. This study investigates the effectiveness of new course materials developed to aid these curriculum changes. Course materials were developed for three purposes: (1) preparation before laboratory sessions (orientation videos and Complete Anatomy (3D4Medical, Elsevier) screens); (2) guidance during laboratory sessions (laboratory guides); and (3) review after laboratory sessions (Zoom recitation sessions). We performed a grounded theory thematic analysis of students' responses (80/160, 50% response) to qualitative survey questions and to focus group questions (16 students who self-selected between 4 different sessions). Data from both the survey and focus groups demonstrated that the vast majority of students agreed that the materials helped them navigate through learning gross anatomy. However, laboratory guides were used mostly for post-lab review as opposed to the intended direction during laboratory sessions. Students within all focus groups overwhelmingly touted the value of Zoom recitation sessions, with many stating that they were imperative to course success. When comparing performance data between 2019 (pre-COVID) and 2020 students, we found that the students who took the anatomy course during the onset of COVID had a slightly higher overall average score in all three modules of the course than compared to the 2019 students. We propose that the utilization of course materials that students perceived as time saving and pertinent to their exam performance, when combined with cadaveric prosection, emphasized the benefits of flipped-classroom learning to help students learn gross anatomy effectively and efficiently during the pandemic and beyond. Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-022-01524-x.

Effect of chlorhexidine cleansing on healthcare-associated infections in neonates: a systematic review and meta-analysis.

BACKGROUND: Healthcare-associated infections (HAIs) have a significant impact on neonatal morbidity, mortality and long-term prognosis, which have a high incidence in neonates. Many studies have shown that chlorhexidine cleansing is effective in reducing HAIs in adults, but the effect of chlorhexidine cleansing on HAIs in neonates remains controversial. AIM: The purpose of this study was to conduct a systematic review and meta-analysis of the effect of chlorhexidine cleansing on HAIs in neonates. The protocol of this review has been registered with the PROSPERO international prospective register of systematic reviews. METHODS: A systematic literature search was performed on five medical literature databases, namely MEDLINE, Web of Science, Embase, Scopus and Cumulative Index to Nursing and Allied Health Literature (CINAHL), published up until 3 March 2021. In the end, six studies were eligible for inclusion, including four randomised controlled trials and two quasi-experimental studies. Version 2 of the Cochrane tool for assessing risk of bias in randomised trials and the Joanna Briggs Institute critical appraisal checklist for quasi-experimental studies were used for quality assessment. Pooled risk ratios (RRs) and their associated 95% CIs were calculated using the fixed effects model (I2 <50%) or the random effects model (I2 ≥50%). FINDINGS AND CONCLUSIONS: The results of the meta-analysis revealed that chlorhexidine cleansing had no significant effect on neonatal sepsis (RR: 0.49, 95% CI 0.18 to 1.38, p=0.18, I2=0%), but significantly reduced neonatal skin bacterial colonisation (RR: 0.61, 95% CI 0.42 to 0.90, p=0.01, I2=50%). In addition, this systematic review showed that chlorhexidine cleansing could significantly reduce central line-associated bloodstream infection in neonates based on large-sample studies. However, more studies are needed to determine the optimal concentration and frequency of chlorhexidine cleansing. PROSPERO registration number CRD42021243858.

Roles of plastid-located phosphate transporters in carotenoid accumulation.

Enhanced carotenoid accumulation in plants is crucial for the nutritional and health demands of the human body since these beneficial substances are acquired through dietary intake. Plastids are the major organelles to accumulate carotenoids in plants and it is reported that manipulation of a single plastid phosphate transporter gene enhances carotenoid accumulation. Amongst all phosphate transport proteins including phosphate transporters (PHTs), plastidial phosphate translocators (pPTs), PHOSPHATE1 (PHO1), vacuolar phosphate efflux transporter (VPE), and Sulfate transporter [SULTR]-like phosphorus distribution transporter (SPDT) in plants, plastidic PHTs (PHT2 & PHT4) are found as the only clade that is plastid located, and manipulation of which affects carotenoid accumulation. Manipulation of a single chromoplast PHT (PHT4;2) enhances carotenoid accumulation, whereas manipulation of a single chloroplast PHT has no impact on carotenoid accumulation. The underlying mechanism is mainly attributed to their different effects on plastid orthophosphate (Pi) concentration. PHT4;2 is the only chromoplast Pi efflux transporter, and manipulating this single chromoplast PHT significantly regulates chromoplast Pi concentration. This variation subsequently modulates the carotenoid accumulation by affecting the supply of glyceraldehyde 3-phosphate, a substrate for carotenoid biosynthesis, by modulating the transcript abundances of carotenoid biosynthesis limited enzyme genes, and by regulating chromoplast biogenesis (facilitating carotenoid storage). However, at least five orthophosphate influx PHTs are identified in the chloroplast, and manipulating one of the five does not substantially modulate the chloroplast Pi concentration in a long term due to their functional redundancy. This stable chloroplast Pi concentration upon one chloroplast PHT absence, therefore, is unable to modulate Pi-involved carotenoid accumulation processes and finally does affect carotenoid accumulation in photosynthetic tissues. Despite these advances, several cases including the precise location of plastid PHTs, the phosphate transport direction mediated by these plastid PHTs, the plastid PHTs participating in carotenoid accumulation signal pathway, the potential roles of these plastid PHTs in leaf carotenoid accumulation, and the roles of these plastid PHTs in other secondary metabolites are waiting for further research. The clarification of the above-mentioned cases is beneficial for breeding high-carotenoid accumulation plants (either in photosynthetic or non-photosynthetic edible parts of plants) through the gene engineering of these transporters.

Regulation of Cytosolic pH: The Contributions of Plant Plasma Membrane H+-ATPases and Multiple Transporters.

Cytosolic pH homeostasis is a precondition for the normal growth and stress responses in plants, and H+ flux across the plasma membrane is essential for cytoplasmic pH control. Hence, this review focuses on seven types of proteins that possess direct H+ transport activity, namely, H+-ATPase, NHX, CHX, AMT, NRT, PHT, and KT/HAK/KUP, to summarize their plasma-membrane-located family members, the effect of corresponding gene knockout and/or overexpression on cytosolic pH, the H+ transport pathway, and their functional regulation by the extracellular/cytosolic pH. In general, H+-ATPases mediate H+ extrusion, whereas most members of other six proteins mediate H+ influx, thus contributing to cytosolic pH homeostasis by directly modulating H+ flux across the plasma membrane. The fact that some AMTs/NRTs mediate H+-coupled substrate influx, whereas other intra-family members facilitate H+-uncoupled substrate transport, demonstrates that not all plasma membrane transporters possess H+-coupled substrate transport mechanisms, and using the transport mechanism of a protein to represent the case of the entire family is not suitable. The transport activity of these proteins is regulated by extracellular and/or cytosolic pH, with different structural bases for H+ transfer among these seven types of proteins. Notably, intra-family members possess distinct pH regulatory characterization and underlying residues for H+ transfer. This review is anticipated to facilitate the understanding of the molecular basis for cytosolic pH homeostasis. Despite this progress, the strategy of their cooperation for cytosolic pH homeostasis needs further investigation.

Exogenous 1',4'-trans-Diol-ABA Induces Stress Tolerance by Affecting the Level of Gene Expression in Tobacco (Nicotiana tabacum L.).

1',4'-trans-diol-ABA is a key precursor of the biosynthesis of abscisic acid (ABA) biosynthesis in fungi. We successfully obtained the pure compound from a mutant of Botrytis cinerea and explored its function and possible mechanism on plants by spraying 2 mg/L 1',4'-trans-diol-ABA on tobacco leaves. Our results showed that this compound enhanced the drought tolerance of tobacco seedlings. A comparative transcriptome analysis showed that a large number of genes responded to the compound, exhibiting 1523 genes that were differentially expressed at 12 h, which increased to 1993 at 24 h and 3074 at 48 h, respectively. The enrichment analysis demonstrated that the differentially expressed genes (DEGs) were primarily enriched in pathways related to hormones and resistance. The DEGs of transcription factors were generally up-regulated and included the bHLH, bZIP, ERF, MYB, NAC, WRKY and HSF families. Moreover, the levels of expression of PYL/PYR, PP2C, SnRK2, and ABF at the ABA signaling pathway responded positively to exogenous 1',4'-trans-diol-ABA. Among them, seven ABF transcripts that were detected were significantly up-regulated. In addition, the genes involved in salicylic acid, ethylene and jasmonic acid pathways, reactive oxygen species scavenging system, and other resistance related genes were primarily induced by 1',4'-trans-diol-ABA. These findings indicated that treatment with 1',4'-trans-diol-ABA could improve tolerance to plant abiotic stress and potential biotic resistance by regulating gene expression, similar to the effects of exogenous ABA.

Optimization of iturin A production from Bacillus subtilis ZK-H2 in submerge fermentation by response surface methodology.

In this research, single-factor and response surface experiments were conducted in the fed-batch fermentation process to improve the yield of iturin A. The effect of adding various concentrations of precursor amino acids l-asparagine (Asn), l-aspartic acid (Asp), l-glutamic acid (Glu), l-glutamine (Gln), l-Serine (Ser) and l-proline (Pro) at different adding times (3 and 12 h) on iturin A production and cell growth was studied. The respective addition of amino acids (Asp 0.28 g/L; Asn 0.36 g/L; Glu 0.20, 0.28 and 0.360 g/L; Gln 0.20, 0.28 and 0.36 g/L; Pro 0.12, 0.20, 0.28 and 0.36 g/L) at 3 h was shown to improve cell growth but did not affect the yield of iturin A. Meanwhile, the individual addition of the same amino acids at 12 h improved cell growth and increased the yield of iturin A. Excellent correlation was obtained between the predicted and measured values, suggesting that the regression model was accurate and reliable; highly significant (P < 0.0001), and the determination coefficient (R2 = 0.975). When 0.0752 g/L Asn; 0.1992 g/L Gln and 0.1464 g/L Pro were added at 12 h, the yield of iturin A reached 0.85 g/L, which is 32.81%-fold higher than that of the initial process. Therefore, this study obtained optimal parameters for iturin A production by the experimental method, and process validation gave high iturin A yields (0.85 g/L) during a 60 h fermentation. These findings could guide an up-scaling of the fermentation process. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13205-020-02540-7) contains supplementary material, which is available to authorized users.