The vesicle trafficking gene, OsRab7, is critical for pollen development and male fertility in cytoplasmic male-sterility rice.

Rice cytoplasmic male sterility (CMS) provides an exceptional model for studying genetic interaction within plant nuclei given its inheritable trait of non-functional male gametophyte. Gaining a comprehensive understanding of the genes and pathways associated with the CMS mechanism is imperative for improving the vigor of hybrid rice agronomically, such as its productivity. Here, we observed a significant decrease in the expression of a gene named OsRab7 in the anther of the CMS line (SJA) compared to the maintainer line (SJB). OsRab7 is responsible for vesicle trafficking and loss function of OsRab7 significantly reduced pollen fertility and setting rate relative to the wild type. Meanwhile, over-expression of OsRab7 enhanced pollen fertility in the SJA line while a decrease in its expression in the SJB line led to the reduced pollen fertility. Premature tapetum and abnormal development of microspores were observed in the rab7 mutant. The expression of critical genes involved in tapetum development (OsMYB103, OsPTC1, OsEAT1 and OsAP25) and pollen development (OsMSP1, OsDTM1 and OsC4) decreased significantly in the anther of rab7 mutant. Reduced activities of the pDR5::GUS marker in the young panicle and anther of the rab7 mutant were also observed. Furthermore, the mRNA levels of genes involved in auxin biosynthesis (YUCCAs), auxin transport (PINs), auxin response factors (ARFs), and members of the IAA family (IAAs) were all downregulated in the rab7 mutant, indicating its impact on auxin signaling and distribution. In summary, these findings underscore the importance of OsRab7 in rice pollen development and its potential link to cytoplasmic male sterility.

An empirical study of indoor air quality in badminton stadiums in hot summer and cold winter regions of China during spring and fall seasons.

The indoor air quality has a direct impact on human health. In order to obtain the current status of indoor air quality in typical sports buildings in hot summer and cold winter climate zones in China, indoor badminton courts in 10 cities in Hubei Province in this climate zone were selected as research objects for field testing of indoor environmental parameters in spring and autumn, and predict air quality parameters for non-testing times. All the tested stadiums are naturally ventilated in non-event conditions, and the average daily indoor CO2 concentration was 526.78 ppm in spring and 527.63 ppm in autumn, and the average daily PM2.5 concentration was 0.035 mg/m3 in spring and 0.024 mg/m3 in autumn, all of which met the requirements of GB/T 18883-2022, the average concentration of CO2 ≤ 1000 ppm and PM2.5 ≤ 0.05 mg/m3. The indoor CO2 concentration and PM2.5 concentration of the tested badminton halls under natural ventilation gradually increased with the accumulation of exercise time, making the indoor air quality of the badminton halls decrease, which would negatively affect the health of the people exercising in this environment.

In Vitro Antibacterial Activity of a Novel Acid-Activated Antimicrobial Peptide against Streptococcus mutans.

BACKGROUND: Dental caries is an oral disease associated with infection by microbial biofilm. The metabolic activity of cariogenic bacteria results in a pH decrease in the plaque biofilm, causing tooth demineralization. This acidic environment favors the growth of cariogenic bacteria that are highly resistant to strong acids, which, in turn, produce more acid resulting in a further decrease in the pH of the plaque biofilm. Therefore, the strategy of utilizing the acidic dental plaque microenvironment to prevent and treat dental caries has become a hot research topic in recent years, such as the development of pH-sensitive drug delivery systems. AIMS: Design of a new acid-activated antibacterial peptide. OBJECTIVES: To design and synthesis an acid targeted antimicrobial peptide with the GWHHFFHFFHFF sequence. METHODS: Minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) testing confirmed its antibacterial activity. Propidium iodide (PI) staining was used to detect nucleic acid leakage. Determination of anti-biofilm activity by biofilm inhibition assay. A phototoxicity study confirmed the phototoxicity of PPIX-P12. RESULTS: MIC and MBC testing confirmed that P12 possessed acid-activated anti-Streptococcus mutans activity. Bactericidal kinetic experiments and propidium iodide (PI) staining experiments showed that P12 killed planktonic S. mutans UA159 cells leading to the leakage of nucleic acids in the acidic medium. Moreover, P12 showed acid-activated anti-biofilms at the early and mature biofilm stages. P12 was conjugated with the phototherapeutic agent protoporphyrin IX (PpIX) to construct the protoporphyrin derivative PpIX-P12. In vitro experiments revealed that PpIX-P12 displayed better antibacterial activity in pH 5.5 medium than in pH 7.2 medium. CONCLUSION: In conclusion, we designed an acid-activated AMP, which had no antimicrobial activity at neutral pH, but had antimicrobial activity at an acidic pH.

A Hybrid Antimicrobial Peptide Targeting Staphylococcus aureus with a Dual Function of Inhibiting Quorum Sensing Signaling and an Antibacterial Effect.

Community-associated methicillin-resistant Staphylococcus aureus (MRSA) is now a major cause of bacterial infection. Antivirulence therapy does not stimulate evolution of a pathogen toward a resistant phenotype, providing a novel method to treat infectious diseases. Here, we used a cyclic peptide of CP7, an AIP-III variant that specifically inhibited the virulence and biofilm formation of Staphylococcus aureus (S. aureus) in a nonbiocidal manner, to conjugate with a broad-spectrum antimicrobial peptide (AMP) via two N-termini to obtain a hybrid AMP called CP7-FP13-2. This peptide not only specifically inhibited the production of virulence of S. aureus at low micromolar concentrations but also killed S. aureus, including MRSA, by disrupting the integrity of the bacterial cell membrane. In addition, CP7-FP13-2 inhibited the formation of the S. aureus biofilm and showed good antimicrobial efficacy against the S. aureus-infected Kunming mice model. Therefore, this study provides a promising strategy against the resistance and virulence of S. aureus.

Ca2+-induced release of IQSEC2/BRAG1 autoinhibition under physiological and pathological conditions.

IQSEC2 (aka BRAG1) is a guanine nucleotide exchange factor (GEF) highly enriched in synapses. As a top neurodevelopmental disorder risk gene, numerous mutations are identified in Iqsec2 in patients with intellectual disabilities accompanied by other developmental, neurological, and psychiatric symptoms, though with poorly understood underlying molecular mechanisms. The atomic structures of IQSECs, together with biochemical analysis, presented in this study reveal an autoinhibition and Ca2+-dependent allosteric activation mechanism for all IQSECs and rationalize how each identified Iqsec2 mutation can alter the structure and function of the enzyme. Transgenic mice modeling two pathogenic variants of Iqsec2 (R359C and Q801P), with one activating and the other inhibiting the GEF activity of the enzyme, recapitulate distinct clinical phenotypes in patients. Our study demonstrates that different mutations on one gene such as Iqsec2 can have distinct neurological phenotypes and accordingly will require different therapeutic strategies.

OsCBL1 modulates rice nitrogen use efficiency via negative regulation of OsNRT2.2 by OsCCA1.

BACKGROUND: For cereal crop breeding, it is meaningful to improve utilization efficiency (NUE) under low nitrogen (LN) levels while maintaining crop yield. OsCBL1-knockdown (OsCBL1-KD) plants exhibited increased nitrogen accumulation and NUE in the field of low N level. RESULTS: OsCBL1-knockdown (OsCBL1-KD) in rice increased the expression of a nitrate transporter gene OsNRT2.2. In addition, the expression of OsNRT2.2, was suppressed by OsCCA1, a negative regulator, which could directly bind to the MYB-binding elements (EE) in the region of OsNRT2.2 promoter. The OsCCA1 expression was found to be down-regulated in OsCBL1-KD plants. At the low Nitrogen (N) level field, the OsCBL1-KD plants exhibited a substantial accumulation of content and higher NUE, and their actual biomass remained approximately as the same as that of the wild type. CONCLUSION: These results indicated that down-regulation of OsCBL1 expression could upregulate the expression of OsNRT2.2 by suppressing the expression of OsCCA1and then increasing the NUE of OsCBL1-KD plants under low nitrogen availability.

Effect of hydrocolloid dressings in the management of different grades of pressure wound ulcers in critically ill adult subjects: A meta-analysis.

A meta-analysis was implemented to appraise the effect of hydrocolloid dressings (HCDs) in the management of different grades of pressure wound ulcers (PWUs) in critically ill adult subjects (CIUSs). Inclusive literature research until April 2023 was done, and 969 interconnected researches were revised. The 8 picked researches, enclosed 679 critically ill adult persons at the utilized researchers' starting point; 355 of them were utilizing HCDs, and 324 were controls. Odds ratio (OR) and 95% confidence intervals (CIs) were utilized to appraise the consequences of HCDs in treating CIUSs by the dichotomous approach and a fixed or random model. HCDs had significantly higher PWU complete healing (OR, 2.15; 95% CI, 1.54-3.02, p < 0.001), PWU stage II ulcers complete healing (OR, 2.82; 95% CI, 1.40-5.69, p = 0.004), and PWU stage III ulcers complete healing (OR, 3.73; 95% CI, 1.23-11.35, p = 0.02) compared to control in critically ill adult persons. HCDs had significantly higher PWU complete healing, PWU stage II ulcers complete healing, and PWU stage III ulcers complete healing compared with control in critically ill adult persons. However, caution needs to be taken when interacting with its values since there was a low sample size of most of the chosen research found for the comparisons in the meta-analysis.

Phenolic compound SG-1 from Balanophora harlandii and its derivatives exert anti-influenza A virus activity via activation of the Nrf2/HO-1 pathway.

Influenza A virus (IAV) is one of the leading causes of respiratory illness and continues to cause pandemics around the world. Against this backdrop, drug resistance poses a challenge to existing antiviral drugs, and hence, there is an urgent need for developing new antiviral drugs. In this study, we obtained a phenolic compound SG-7, a derivative of natural compound 2-hydroxymethyl-1,4-hydroquinone, which exhibits inhibitory activity toward a panel of influenza viruses and has low cellular toxicity. Mechanistic studies have shown that SG-7 exerts its anti-IAV properties by acting on the virus itself and modulating host signaling pathways. Namely, SG-7 targets the HA2 subunit of hemagglutinin (HA) to block the fusion of viral-cellular membranes and inhibits IAV-induced oxidative stress and overexpression of pro-inflammatory factors by activating the Nrf2/HO-1 pathway and reducing NF-κB activation. In addition, SG-7 can enhance type I IFN antiviral response by inducing Nrf2 expression. Importantly, SG-7 showed the ability to inhibit viral replication in the lungs of IAV-infected mice and reduce their mortality. Therefore, SG-7 may be a promising lead compound for anti-influenza drug development.

Clinical characteristics and long-term management of prepubertal testicular teratomas: a retrospective, multicenter study.

Prepubertal testicular teratomas are rare tumors with limited practical guidance for their management. This study aimed to analyze a large multicenter database to establish the optimal management of testicular teratomas. We retrospectively collected data on testicular teratomas in children younger than 12 years who underwent surgery without postoperative chemotherapy in three large professional children's institutions in China between 2007 and 2021. The biological behavior and long-term outcomes of testicular teratomas were analyzed. In total, 487 children (with 393 mature teratomas and 94 immature teratomas) were included. Among mature teratomas, 375 cases were testis-sparing, 18 were orchiectomies, 346 were operated through the scrotal approach, and 47 underwent the inguinal approach. The median follow-up period was 70 months, and no recurrence or testicular atrophy was observed. Among the children with immature teratomas, 54 underwent testis-sparing surgery, 40 underwent orchiectomy, 43 were operated through the scrotal approach, and 51 were operated through the inguinal approach. Two cases of immature teratomas with cryptorchidism had local recurrence or metastasis within 1 year of the operation. The median follow-up duration was 76 months. No other patients had recurrence, metastasis, or testicular atrophy.  Conclusion: Testicular-sparing surgery is the first treatment choice for prepubertal testicular teratomas, with the scrotal approach being a safe and well-tolerated strategy for these diseases. Additionally, patients with immature teratomas and cryptorchidism may have tumor recurrence or metastasis after surgery. Therefore, these patients should be closely followed up in the first year after surgery. What is Known: • There is a fundamental difference between testicular tumours in childhood and those in adulthood - not only in terms of the difference and incidence but also in terms of histology. • For surgical techniques, the inguinal approach is recommended for the treatment of testicular teratomas in children. What is New: • The scrotal approach being a safe and well-tolerated strategy for testicular teratomas in children. • Patients with immature teratomas and cryptorchidism may have tumor recurrence or metastasis after surgery. These patients should be closely followed up in the first year after surgery.

Correlation analysis between biomechanical characteristics of taekwondo double roundhouse kick and effective scoring of electronic body protector.

Objective: To explore the inherent relationship between lower limb biomechanical indicators and effective scoring values of double roundhouse kick (DRK) by taekwondo athletes, and to find key biomechanical factors that trigger effective scoring. Methods: Using the DAEDO Protector and Scoring System (PSS) in conjunction with the Vicon optical motion capture system and Kistler 3D force plate, kinematic and dynamic indicators of the front kicking motion were obtained from 12 professional taekwondo athletes (18.00 ± 2.20 years, 182.15 ± 8.62 cm and 70.00 ± 14.82 kg). The correlation between kinematics, dynamics, and scoring values was initially analyzed using bivariate linear correlation. Subsequently, based on the results of the linear correlation analysis, a stepwise regression analysis was performed to establish a stepwise regression equation. Results: The results reveal that during the First Hit, there is a significant positive correlation (r > 0, p < 0.05) between peak hip flexion angular velocity of the dominant leg, knee abduction angle, and peak foot horizontal plane linear velocity of the non-dominant leg with effective score. On the other hand, peak ankle flexion angular velocity of the non-dominant leg, peak foot sagittal plane linear velocity, peak hip abduction angle, and peak hip flexion angle of the dominant leg exhibit a significant negative correlation (r < 0, p < 0.05) with effective score. These correlations hold statistical significance (DW> 1.023). During the Second Hit, there is a significant positive correlation (r > 0, p < 0.05) between peak ankle internal rotation angular velocity of the dominant leg, foot coronal plane linear velocity, hip adduction angular velocity, and peak ankle internal rotation moment of the non-dominant leg with effective score. Conversely, peak hip flexion angle of the dominant leg shows a significant negative correlation (r < 0, p < 0.05) with effective score. All these variables have a statistically significant impact on effective score (DW > 1.023). Conclusion: Explosive power, body posture, adequate terminal velocity, and body rotation have an association with effective scoring of the electronic protector. The peak angular velocity of the ankle joint of the dominant leg and the peak linear velocity of the foot horizontal plane of the non-dominant leg significantly contribute to the effectiveness score of the electronic protector.

New sesquiterpene from a soil fungus of Trichoderma sp.

Sixteen secondary metabolites, including one new sesquiterpene (1, named isocyclonerodiol oxide), seven known sesquiterpenes (2-8), two sorbicillinoid polyketides (15, 16), and six known other compounds (9-14) were isolated from the fermentation broth of Trichoderma sp. T-4-1. The structure of 1 was determined by 1 D, 2 D NMR (HMBC, HSQC, 1H-1H COSY, NOESY), and HRESIMS spectra. In addition, sesquiterpenes and sorbicillinoid polyketides showed significant antiviral activities.

Sesquiterpenoids isolated from feces-residing Streptomyces sp. inhibit the cellular entry of influenza a viruses.

Five metabolites (1-5), including two new sesquiterpenoids, designated ganodermanol L (1) and 4α,15-epoxyeudesmane-1ß,6α,11-triol (2), together with three known structurally related compounds (3-5), have been isolated from the cultures of Streptomyces sp. XM17, a bacteria residing in the fresh feces of the giant panda Ailuropoda melanoleuca. The structures of 1-2 were established on the basis of extensive spectroscopic analyses, including 1D- and 2D-NMR (1H-1H COSY, HMQC, HMBC and NOESY) experiments. Furthermore, the absolute configuration of 1 was established by single-crystal X-ray crystallographic analyses. Of noted, these compounds were found to possessed antiviral activities using the 'pretreatment of virus' approach with IC50 values ranging from 4 to 30 nM, indicating that these sesquiterpenoids were potent in inhibiting the entry of influenza A virus.

Secondary Metabolites with Cytotoxic Activities from Streptomyces sp. BM-8 Isolated from the Feces of Equusquagga.

A new aliphatic acid, compound 1, together with six known metabolites, including nonactic acid (2), homononactic acid (3), ethyl homononactate (4), homononactylhomononactate (5), valinomycin (6), and cyclo-(Pro-Leu) (7), was isolated from the culture broth of Streptomyces sp. BM-8, an actinobacterial strain isolated from the feces of Equus quagga. The structures of these compounds were established by analyses of spectroscopic data, including 1D and 2D nuclear magnetic resonance spectra (NMR), as well as by HR-ESI-MS spectrometry and chemical derivative analyses. Additionally, a serial analogue of nonactic acid and homononacticacid (8-21) was synthesized. The cytotoxicity of 1-21 wastested against a panel of cancer cell lines, such as HT-29, MCF-7, A375 and K562, with MTT assay. In addition, the cytotoxicity tests revealed that 1 was less cytotoxic toward a panel of cancerous cells, as compared with valinomycin (6).

Tunable reflector with active magnetic metamaterials.

We placed active magnetic metamaterials on metallic surface to implement a tunable reflector with excellent agile performance. By incorporating active elements into the unit cells of the magnetic metamaterial, this active magnetic metamaterial can be tuned to switch function of the reflector among a perfect absorber, a perfect reflector and a gain reflector. This brings about DC control lines to electrically tune the active magnetic metamaterial with positive loss, zero loss and even negative loss. The design, analytical and numerical simulation methods, and experimental results of the tunable reflector are presented.

Far field free-space measurement of three dimensional hole -in -Teflon invisibility cloak.

In this paper, we report a fabrication of a three-dimensional (3D) carpet cloak that works for any polarization in free space. Two-dimensional (2D) conformal mapping is first employed and the 3D structure is generated by a rotation of the 2D cloak. The structure of the cloak is hole-in-dielectric. The triangular invisible region has a height of 36 mm (one third of the height of the whole device) and a width of 240 mm. The cloaking effect is examined in free space by measuring the scattering parameters. The results show our device has very good cloaking performance in a wide frequency range from 4 to 10 GHz.