Uncoupling transcription and translation through miRNA-dependent poly(A) length control in haploid male germ cells.

As one of the post-transcriptional regulatory mechanisms, uncoupling of transcription and translation plays an essential role in development and adulthood physiology. However, it remains elusive how thousands of mRNAs get translationally silenced while stability is maintained for hours or even days before translation. In addition to oocytes and neurons, developing spermatids display significant uncoupling of transcription and translation for delayed translation. Therefore, spermiogenesis represents an excellent in vivo model for investigating the mechanism underlying uncoupled transcription and translation. Through full-length poly(A) deep sequencing, we discovered dynamic changes in poly(A) length through deadenylation and re-polyadenylation. Deadenylation appeared to be mediated by microRNAs (miRNAs), and transcripts with shorter poly(A) tails tend to be sequestered into ribonucleoprotein (RNP) granules for translational repression and stabilization. In contrast, re-polyadenylation might allow for translocation of the translationally repressed transcripts from RNP granules to polysomes. Overall, our data suggest that miRNA-dependent poly(A) length control represents a previously unreported mechanism underlying uncoupled translation and transcription in haploid male mouse germ cells.

ROP signaling regulates spatial pattern of cell division and specification of meristem notch.

The formation of cell polarity is essential for many developmental processes such as polar cell growth and spatial patterning of cell division. A plant-specific ROP (Rho-like GTPases from Plants) subfamily of conserved Rho GTPase plays a crucial role in the regulation of cell polarity. However, the functional study of ROPs in angiosperm is challenging because of their functional redundancy. The Marchantia polymorpha genome encodes a single ROP gene, MpROP, providing an excellent genetic system to study ROP-dependent signaling pathways. Mprop knockout mutants exhibited rhizoid growth defects, and MpROP was localized at the tip of elongating rhizoids, establishing a role for MpROP in the control of polar cell growth and its functional conservation in plants. Furthermore, the Mprop knockout mutant showed defects in the formation of meristem notches associated with disorganized cell division patterns. These results reveal a critical function of MpROP in the regulation of plant development. Interestingly, these phenotypes were complemented not only by MpROP but also Arabidopsis AtROP2, supporting the conservation of ROP's function among land plants. Our results demonstrate a great potential for M. polymorpha as a powerful genetic system for functional and mechanistic elucidation of ROP signaling pathways during plant development.

Interfacial π-p Electron Coupling Prompts Hydrogen Evolution Reaction Activity in Acidic Electrolyte.

The thermodynamically stable 2H-phase MoS2 is a brilliant material toward hydrogen evolution reaction (HER) owing to its excellent Gibbs free energy of hydrogen adsorption. Nevertheless, the poor intrinsic properties of 2H-MoS2 limit its electrocatalytic performances toward HER. In this work, graphitic carbon nitride covalently bridging 2H-MoS2 (MoS2/GCN) is proposed to construct robust HER electrocatalysts. The strong π-p electron coupling between the delocalized π electrons of GCN and the localized p electrons of S atoms sufficiently expose active sites and accelerate the reaction kinetics. To be specific, MoS2/GCN exhibits remarkable HER activity (160 mV at 10 mA·cm-2) and long-term durability. Importantly, MoS2/GCN also provides great potential for industrial application. Density functional theory (DFT) calculations disclose that the π-p electron coupling at the MoS2/GCN interface regulates the electronic structure of S atoms, consequently providing enhanced HER performance. This work presents a feasible pathway to develop advanced electrocatalysts for energy conversions.

Oviductal motile cilia are essential for oocyte pickup but dispensable for sperm and embryo transport.

Mammalian oviducts play an essential role in female fertility by picking up ovulated oocytes and transporting and nurturing gametes (sperm/oocytes) and early embryos. However, the relative contributions to these functions from various cell types within the oviduct remain controversial. The oviduct in mice deficient in two microRNA (miRNA) clusters (miR-34b/c and miR-449) lacks cilia, thus allowing us to define the physiological role of oviductal motile cilia. Here, we report that the infundibulum without functional motile cilia failed to pick up the ovulated oocytes. In the absence of functional motile cilia, sperm could still reach the ampulla region, and early embryos managed to migrate to the uterus, but the efficiency was reduced. Further transcriptomic analyses revealed that the five messenger ribonucleic acids (mRNAs) encoded by miR-34b/c and miR-449 function to stabilize a large number of mRNAs involved in cilium organization and assembly and that Tubb4b was one of their target genes. Our data demonstrate that motile cilia in the infundibulum are essential for oocyte pickup and thus, female fertility, whereas motile cilia in other parts of the oviduct facilitate gamete and embryo transport but are not absolutely required for female fertility.

[Gene-gene/gene-environment interaction of transforming growth factor-ß signaling pathway and the risk of non-syndromic oral clefts].

OBJECTIVE: To explore the association between polymorphisms of transforming growth factor-ß (TGF-ß) signaling pathway and non-syndromic cleft lip with or without cleft palate (NSCL/P) among Asian populations, while considering gene-gene interaction and gene-environment interaction. METHODS: A total of 1 038 Asian NSCL/P case-parent trios were ascertained from an international consortium, which conducted a genome-wide association study using a case-parent trio design to investigate the genes affec-ting risk to NSCL/P. After stringent quality control measures, 343 single nucleotide polymorphism (SNP) spanning across 10 pivotal genes in the TGF-ß signaling pathway were selected from the original genome-wide association study(GWAS) dataset for further analysis. The transmission disequilibrium test (TDT) was used to test for SNP effects. The conditional Logistic regression models were used to test for gene-gene interaction and gene-environment interaction. Environmental factors collected for the study included smoking during pregnancy, passive smoking during pregnancy, alcohol intake during pregnancy, and vitamin use during pregnancy. Due to the low rates of exposure to smoking during pregnancy and alcohol consumption during pregnancy (<3%), only the interaction between maternal smoking during pregnancy and multivitamin supplementation during pregnancy was analyzed. The threshold for statistical significance was rigorously set at P =1.46×10-4, applying Bonferroni correction to account for multiple testing. RESULTS: A total of 23 SNPs in 4 genes yielded nominal association with NSCL/P (P<0.05), but none of these associations was statistically significant after Bonferroni' s multiple test correction. However, there were 6 pairs of SNPs rs4939874 (SMAD2) and rs1864615 (TGFBR2), rs2796813 (TGFB2) and rs2132298 (TGFBR2), rs4147358 (SMAD3) and rs1346907 (TGFBR2), rs4939874 (SMAD2) and rs1019855 (TGFBR2), rs4939874 (SMAD2) and rs12490466 (TGFBR2), rs2009112 (TGFB2) and rs4075748 (TGFBR2) showed statistically significant SNP-SNP interaction (P<1.46×10-4). In contrast, the analysis of gene-environment interactions did not yield any significant results after being corrected by multiple testing. CONCLUSION: The comprehensive evaluation of SNP associations and interactions within the TGF-ß signaling pathway did not yield any direct associations with NSCL/P risk in Asian populations. However, the significant gene-gene interactions identified suggest that the genetic architecture influencing NSCL/P risk may involve interactions between genes within the TGF-ß signaling pathway. These findings underscore the necessity for further investigations to unravel these results and further explore the underlying biological mechanisms.

Proteomic identification of intracellular vesicle trafficking and protein glycosylation requirements for lumen inflation in Ciona notochord.

Lumen formation and inflation are crucial steps for tubular organ morphogenesis, yet the underling mechanism remains largely unrevealed. Here, we applied 4D proteomics to screen the lumenogenesis-related proteins and revealed the biological pathways potentially that are involved in lumen inflation during notochord lumen formation in the ascidian Ciona savignyi. In total, 910 differentiated expressed proteins (DEPs) were identified before and after notochord lumen formation utilizing Mfuzz analysis. Those DEPs were grouped into four upregulated clusters based on their quantitative expression patterns; the functions of these proteins were enriched in protein metabolic and biosynthetic process, the establishment of localization, and vesicle-mediated transport. We analyzed the vesicle trafficking cluster and focused on several vesicle transport hub proteins. In vivo function-deficient experiments showed that mutation of vesicle transport proteins resulted in an abnormal lumen in notochord development, demonstrating the crucial role of intracellular trafficking for lumen formation. Moreover, abundant extracellular matrix proteins were identified, the majority of which were predicted to be glycosylated proteins. Inhibition of glycosylation markedly reduced the lumen expansion rate in notochord cells, suggesting that protein glycosylation is essential for lumenogenesis. Overall, our study provides an invaluable resource and reveals the crucial mechanisms in lumen formation and expansion.

Synergetic Monitoring of both Physiological Pressure and Epidermal Biopotential Based on a Simplified on-Skin-Printed Sensor Modality.

Flexible electronic sensors show great potential for health monitoring but are usually limited to single sensing functionality. To enrich their functions, complicated device configurations, sophisticated material systems, and preparation processes are typically involved, obstructing their large-scale deployment and widespread application. Herein, to achieve a good balance between simplicity and multifunctionality, a new paradigm of sensor modality for both mechanical sensing and bioelectrical sensing is presented based on a single material system and a simple solution processing approach. The whole multifunctional sensors are constructed with a pair of highly conductive ultrathin electrodes (WPU/MXene-1) and an elastic micro-structured mechanical sensing layer (WPU/MXene-2), with the human skin serving as the substrate for the whole sensors. The resultant sensors show high pressure sensitivity and low skin-electrode interfacial impedance, enabling to synergetically monitor both physiological pressure (e.g., arterial pulse signals) and epidermal bioelectrical signals (including electrocardiograph and electromyography). The universality and extensibility of this methodology to construct multifunctional sensors with different material systems are also verified. This simplified sensor modality with enhanced multifunctionality provides a novel design concept to construct future smart wearables for health monitoring and medical diagnosis.

Ozone-3,6-dihydroxynaphtha-2,7-disulphonate chemiluminescence system is used for online ozone detection.

The chemiluminescence (CL) reaction between ozone and 3,6-dihydroxynaphtha-2,7-disulphonate (DNDS) was found under alkaline conditions. Therefore, a novel CL system for ozone detection was established. The CL signal of the CL system is weak, and the CL signal is enhanced by adding nonionic surfactants. It was found that adding 16.4 g/l Triton X-100 can enhance the CL signal. The CL reagent activated by ultraviolet (UV) light produced a CL signal was nearly 10 times stronger than the CL reagent not activated by UV light; the CL signal was enhanced by adding 8 g/l NaHCO3 to the CL reagent irradiated by UV light. Through the optimization of these test conditions, a high-selectivity, high-sensitivity online detection method for ozone CL was established. The linear range was 0.5-150 ppbv, and the limit of detection (LOD) was 0.092 ppbv (S/N = 3).

First report of Capsicum chlorosis virus naturally infecting Ageratum conyzoides in China.

Capsicum chlorosis virus (CaCV; family Tospoviridae, genus Orthotospovirus) was first reported to infect capsicum (Capsicum annuum) and tomato (Solanum lycopersicum) in Australia in 2002 (McMichael et al., 2002). Subsequently, its infection was detected in different plants including waxflower (Hoya calycina Schlecter) in the United States (Melzer et al. 2014), peanut (Arachis hypogaea) in India (Vijayalakshmi et al. 2016), and spider lily (Hymenocallis americana) (Huang et al. 2017), Chilli pepper (Capsicum annuum) (Zheng et al. 2020), and Feiji cao (Chromolaena odorata) (Chen et al. 2022) in China. Ageratum conyzoides L. (commonly known as goat weed, family Asteraceae) is a natural weed in crop fields distributed in subtropical and tropical areas and a reservoir host of numerous plant pathogens (She et al. 2013). In April 2022, we observed that 90% of plants of A. conyzoides in maize fields in Sanya, Hainan province, China, exhibited typical virus-like symptoms of vein yellowing, leaf chlorosis, and distortion (Fig. S1 A-C). Total RNA was extracted from one symptomatic leaf of A. conyzoides. Small RNA libraries were constructed using the small RNA Sample Pre Kit (Illumina, San Diego, USA) for sequencing with an Illumina Novaseq 6000 platform (Biomarker Technologies Corporation, Beijing, China). A total 15,848,189 clean reads were obtained after removing low-quality reads. Quality-controlled qualified reads were assembled into contigs using Velvet 1.0.5 software with a k-mer value of 17. One hundred contigs shared nucleotide identity ranging from 85.7% to 100% with the CaCV using BLASTn searches online (https://blast.ncbi.nlm.nih.gov/Blast.cgi?). Numerous contigs (45, 34, and 21) obtained in this study were mapped to the L, M, and S RNA segments of the CaCV-Hainan isolate (GenBank accession no. KX078565- KX078567) from spider lily (Hymenocallis americana) in Hainan province, China, respectively. The full-length of L, M, and S RNA segments of CaCV-AC were determined to be 8,913, 4,841, and 3,629 bp, respectively (GenBank accession no. OQ597167- OQ597169). Furthermore, five symptomatic leaf samples were tested to be positive for CaCV using a CaCV enzyme-linked immunosorbent assay (ELISA) kit (MEIMIAN, Jiangsu, China) (Fig. S1-D). Total RNA from these leaves was amplified by RT-PCR with two sets of primer pairs. Primers CaCV-F (5'-ACTTTCCATCAACCTCTGT-3') and CaCV-R (5'-GTTATGGCCATATTTCCCT-3') were used for the amplification of 828 bp fragment from nucleocapsid protein (NP) on CaCV S RNA. While another, primers gL3637 (5'-CCTTTAACAGTDGAAACAT-3') and gL4435c (5'-CATDGCRCAAGARTGRTARACAGA-3') were used for the amplification of 816 bp fragment from RNA-dependent RNA polymerase (RdRP) on CaCV L RNA (Fig. S1-E and -F) (Basavaraj et al. 2020). These amplicons were cloned into the pCE2 TA/Blunt-Zero vector (Vazyme, Nanjing, China) and three independent positive colonies of Escherichia coli DH5α carrying each viral amplicon were sequenced. These sequences were deposited in the GenBank database under accession nos. OP616700-OP616709. Pairwise sequence comparison revealed that nucleotide sequences of NP and RdRP genes of the five CaCV isolates shared 99.5% (812 bp out of 828 bp) and 99.4% (799 bp out of 816 bp) nucleotide identities, respectively. They showed 86.2-99.2% and 86.5-99.1% nucleotide identities with corresponding nucleotide sequences of other CaCV isolates derived from GenBank database, respectively. The highest nucleotide sequence identity (99%) of the CaCV isolates obtained in the study was observed with the CaCV-Hainan isolate. Phylogenetic analysis based on NP amino acid demonstrated that six CaCV isolates (this study = 5 and NCBI database = 1) clustered into one distinct clade (Fig. S2). Our data confirmed for the first time the presence of CaCV naturally infecting A. conyzoides plant in China, which enriches information on the host range and will be helpful for disease management.

Modeling of Rapid Pam Systems Based on Electrothermal Micromirror for High-Resolution Facial Angiography.

In this paper, a portable photoacoustic microscopy (PAM) system is proposed based on a large stroke electrothermal micromirror to achieve high resolution and fast imaging. The crucial micromirror in the system realizes a precise and efficient 2-axis control. Two different designs of electrothermal actuators with "O" and "Z" shape are evenly located around the four directions of mirror plate. With a symmetrical structure, the actuator realized single direction drive only. The finite element modelling of both two proposed micromirror has realized a large displacement over 550 µm and the scan angle over ±30.43° at 0-10 V DC excitation. In addition, the steady-state and transient-state response show a high linearity and quick response respectively, which can contribute to a fast and stable imaging. Using the Linescan model, the system achieves an effective imaging area of 1 mm × 3 mm in 14 s and 1 mm × 4 mm in 12 s for the "O" and "Z" types, respectively. The proposed PAM systems have advantages in image resolution and control accuracy, indicating a significant potential in the field of facial angiography.

Gender disparities in the mediating role of symptom knowledge level in reducing acute coronary syndrome (ACS) decision delay: Findings from a community-based study in China.

BACKGROUND: Implementing training programs to educate patients on the prodromal symptoms of acute coronary syndrome (ACS) may assist patients in accurately recognizing these symptoms, and ultimately decrease their time delay in seeking emergency medical services (EMS). However, the effectiveness of this approach remains uncertain, particularly among the Chinese population. METHODS: A cross-sectional study was conducted within 22 communities in Beijing, China between 2015 and 2018, with a total of 1099 participants recruited. The study utilized a standardized questionnaire to evaluate the presence of intentional decision delay in turning to EMS under a hypothetical chest pain, the participants' knowledge of ACS prodromal symptoms, and whether they had ever received any training programs aimed at increasing their symptom knowledge. Mediation analysis was performed with regression models and bootstrapping methods, and gender difference was further analyzed through moderated mediation analysis. RESULTS: A total of 1099 participants (58.2% female, median [IQR] age 34 [20]) were included in the study. The results of the mediation analysis indicated that training programs were associated with a decrease risk in decision delay, with increased knowledge playing a mediating role (mediation effect/total effect = 36.59%, P < 0.0001). Gender modified this mediation effect, with it being observed only in the male group. Specifically, training programs were not found to significantly decrease decision delay among females (P > 0.05), even though they did improve women's knowledge of ACS prodromal symptoms (ß = 0.57, P = 0.012). CONCLUSION: The results suggested a relationship between prior training programs and reduced decision delay, with increased knowledge of prodromal symptoms of ACS serving as a mediator. However, the effect was only observed in male participants and not in female participants. This highlights the notion that mere transfer of knowledge regarding ACS prodromal symptoms may not be sufficient to mitigate decision delay in the female population. Further research is needed to corroborate these results and to gain deeper insights into the gender-specific barriers encountered in this study.

The Regulatory Network of Sweet Corn (Zea mays L.) Seedlings under Heat Stress Revealed by Transcriptome and Metabolome Analysis.

Heat stress is an increasingly significant abiotic stress factor affecting crop yield and quality. This study aims to uncover the regulatory mechanism of sweet corn response to heat stress by integrating transcriptome and metabolome analyses of seedlings exposed to normal (25 °C) or high temperature (42 °C). The transcriptome results revealed numerous pathways affected by heat stress, especially those related to phenylpropanoid processes and photosynthesis, with 102 and 107 differentially expressed genes (DEGs) identified, respectively, and mostly down-regulated in expression. The metabolome results showed that 12 or 24 h of heat stress significantly affected the abundance of metabolites, with 61 metabolites detected after 12 h and 111 after 24 h, of which 42 metabolites were detected at both time points, including various alkaloids and flavonoids. Scopoletin-7-o-glucoside (scopolin), 3-indolepropionic acid, acetryptine, 5,7-dihydroxy-3',4',5'-trimethoxyflavone, and 5,6,7,4'-tetramethoxyflavanone expression levels were mostly up-regulated. A regulatory network was built by analyzing the correlations between gene modules and metabolites, and four hub genes in sweet corn seedlings under heat stress were identified: RNA-dependent RNA polymerase 2 (RDR2), UDP-glucosyltransferase 73C5 (UGT73C5), LOC103633555, and CTC-interacting domain 7 (CID7). These results provide a foundation for improving sweet corn development through biological intervention or genome-level modulation.

Multiple evaluations of atmospheric behavior between Criegee intermediates and HCHO: Gas-phase and air-water interface reaction.

Given the high abundance of water in the atmosphere, the reaction of Criegee intermediates (CIs) with (H2O)2 is considered to be the predominant removal pathway for CIs. However, recent experimental findings reported that the reactions of CIs with organic acids and carbonyls are faster than expected. At the same time, the interface behavior between CIs and carbonyls has not been reported so far. Here, the gas-phase and air-water interface behavior between Criegee intermediates and HCHO were explored by adopting high-level quantum chemical calculations and Born-Oppenheimer molecular dynamics (BOMD) simulations. Quantum chemical calculations evidence that the gas-phase reactions of CIs + HCHO are submerged energy or low energy barriers processes. The rate ratios speculate that the HCHO could be not only a significant tropospheric scavenger of CIs, but also an inhibitor in the oxidizing ability of CIs on SOx in dry and highly polluted areas with abundant HCHO concentration. The reactions of CH2OO with HCHO at the droplet's surface follow a loop structure mechanism to produce i) SOZ (), ii) BHMP (HOCH2OOCH2OH), and iii) HMHP (HOCH2OOH). Considering the harsh reaction conditions between CIs and HCHO at the interface (i.e., the two molecules must be sufficiently close to each other), the hydration of CIs is still their main atmospheric loss pathway. These results could help us get a better interpretation of the underlying CIs-aldehydes chemical processes in the global polluted urban atmospheres.

Efficient genome editing by CRISPR-Mb3Cas12a in mice.

As an alternative and complementary approach to Cas9-based genome editing, Cas12a has not been widely used in mammalian cells largely due to its strict requirement for the TTTV protospacer adjacent motif (PAM) sequence. Here, we report that Mb3Cas12a (Moraxella bovoculi AAX11_00205) can efficiently edit the mouse genome based on the TTV PAM sequence with minimal numbers of large on-target deletions or insertions. When TTTV PAM sequence-targeting CRISPR (cr)RNAs of 23 nt spacers are used, >70% of the founders obtained are edited. Moreover, the use of Mb3Cas12a tagged to monomeric streptavidin (mSA) in conjunction with biotinylated DNA donor template leads to high knock-in efficiency in two-cell mouse embryos, with 40% of founders obtained containing the desired knock-in sequences.

X-linked miR-506 family miRNAs promote FMRP expression in mouse spermatogonia.

Comment on "A microRNA cluster in the Fragile-X region expressed during spermatogenesis targets FMR1" by Ramaiah et al.

Fabric-based in situ synthesis of gold nanoparticles for continuous enhanced heterogeneous chemiluminescence online detection of carbon dioxide.

In this paper, nylon microfiber fabric with a heterogeneous chemiluminescence system was used for the synthesis of gold nanoparticles (AuNPs) for the first time, and it was used to enhance the online detection of carbon dioxide (CO2) by heterogeneous chemiluminescence. Nylon microfiber fabric was chosen as the gas-liquid heterogeneous chemiluminescence micro reaction interface. The thermal reduction method prepared the micro reaction interface with in situ synthesized AuNPs. The solution of H2O2 and KOH forms a liquid film on the surface of the micro reaction interface, and a heterogeneous chemiluminescence reaction occurs when CO2 flows through the surface of the liquid film. The AuNPs supported in situ on the micro reaction interface act catalytically and enhance the chemiluminescence signal for CO2 detection. In this way, AuNPs can be used repeatedly in the chemiluminescence reaction, avoiding the waste of precious metal nanoparticles and reducing the detection cost. Under the optimal conditions, CO2 has a good linear relationship with the chemiluminescence signal in the range of 10-20 000 ppm (v/v). The correlation coefficient R2 is 0.9963, the detection limit is 0.35 ppm (v/v), and the relative standard deviation is 1.79%. This approach provides an entirely new technological platform for the development of functional fabrics and the maximum utilization of precious metal nanoparticles.

Facile preparation of a MXene-graphene oxide membrane and its voltage-gated ion transport behavior.

Two-dimensional MXenes have become a crucial topic in the field of ion transportation owing to their excellent electrochemical performance. Herein, a strategy for preparing a layered MXene-graphene oxide (GO) membrane via vacuum filtration is proposed, which endows the delaminated two-dimensional MXene-GO membrane (MGOm) with excellent electrical conductivity and chemical stability, achieving an excellent voltage-gated ion transport behavior. Owing to the presence of charges or dipoles within the membrane's channel, the movement of electrons or dipoles under the influence of membrane potential is possible. By varying the transmembrane potential, the transition between the closed and open states of the voltage-gated ion channel can be adjusted. When a negative potential is applied at osmotic pressure, the force between the charged MGOm sheet and the cation (K+) is enhanced, promoting ion permeation. Conversely, the application of positive potential attenuates electrostatic attraction, resulting in a decrease in ion permeability. In addition, the effects of MXene and GO with different modulation ratios on the voltage-gated ion transport have shown that when the modulation ratio of MXene : GO is 7 : 3, the optimal ion permeation rate is achieved. In conclusion, the conductive film with voltage-gated nanochannels is a promising alternative for ion transportation, opening up new avenues for the further exploration of MXene materials in energy storage devices.

A computational study of the HO2 + SO3 → HOSO2 + 3O2 reaction catalyzed by a water monomer, a water dimer and small clusters of sulfuric acid: kinetics and atmospheric implications.

Herein, the reaction mechanisms and kinetics for the HO2 + SO3 → HOSO2 + 3O2 reaction catalyzed by a water monomer, a water dimer and small clusters of sulfuric acid have been studied theoretically by quantum chemical methods and the Master Equation/Rice-Ramsperger-Kassel-Marcus (ME/RRKM) rate calculations. The calculated results show that when H2O is introduced into the HO2 + SO3 reaction, it not only enhances the stability of the reactant complexes by 9.0 kcal mol-1 but also reduces the energy of the transition state by 8.7 kcal mol-1. As compared with H2O, catalysts (H2O)2, H2SO4, H2SO4⋯H2O and (H2SO4)2 are more effective energetically, which not only results from a higher binding energy of 21.3-26.0 kcal mol-1 for the reactant complexes but also from a reduction of the energy of the transition states by 8.6-17.2 kcal mol-1. Effective rate constant calculations show that, as compared with H2O, catalysts (H2O)2, H2SO4, H2SO4⋯H2O and (H2SO4)2 can never become more efficient catalysts within the altitude range of 0-15 km due to their relatively lower concentrations. Besides, at 0 km altitude, the enhancement factor for the H2O and (k'WD1/ktot) (H2O)2-assisted HO2 + SO3 reaction within the temperature range of 280-320 K was respectively calculated to be 0.31%-0.34% and 0.16%-0.27%, while the corresponding enhancement factor of H2O and (H2O)2 at higher altitudes of 5-15 km was respectively found only 0.002%-0.12% and 0.00001%-0.022%, indicating that the contributions of H2O and (H2O)2 are not apparent in the gas-phase reaction of HO2 with SO3 especially at higher altitude. Overall, the present work will give a new insight into how a water monomer, a water dimer and small clusters of sulfuric acid catalyze the HO2 + SO3 → HOSO2 + 3O2 reaction.

Motile cilia of the male reproductive system require miR-34/miR-449 for development and function to generate luminal turbulence.

Cilia are cell-surface, microtubule-based organelles that project into extracellular space. Motile cilia are conserved throughout eukaryotes, and their beat induces the flow of fluid, relative to cell surfaces. In mammals, the coordinated beat of motile cilia provides highly specialized functions associated with the movement of luminal contents, as seen with metachronal waves transporting mucus in the respiratory tract. Motile cilia are also present in the male and female reproductive tracts. In the female, wave-like motions of oviductal cilia transport oocytes and embryos toward the uterus. A similar function has been assumed for motile cilia in efferent ductules of the male-i.e., to transport immotile sperm from rete testis into the epididymis. However, we report here that efferent ductal cilia in the male do not display a uniform wave-like beat to transport sperm solely in one direction, but rather exert a centripetal force on luminal fluids through whip-like beating with continual changes in direction, generating turbulence, which maintains immotile spermatozoa in suspension within the lumen. Genetic ablation of two miRNA clusters (miR-34b/c and -449a/b/c) led to failure in multiciliogenesis in murine efferent ductules due to dysregulation of numerous genes, and this mouse model allowed us to demonstrate that loss of efferent duct motile cilia causes sperm aggregation and agglutination, luminal obstruction, and sperm granulomas, which, in turn, induce back-pressure atrophy of the testis and ultimately male infertility.

High-Sensitivity Flexible Piezoresistive Pressure Sensor Using PDMS/MWNTS Nanocomposite Membrane Reinforced with Isopropanol for Pulse Detection.

Flexible pressure sensors with high sensitivity and good linearity are in high demand to meet the long-term and accurate detection requirements for pulse detection. In this study, we propose a composite membrane pressure sensor using polydimethylsiloxane (PDMS) and multiwalled carbon nanotubes (MWNTS) reinforced with isopropanol prepared by solution blending and a self-made 3D-printed mold. The device doped with isopropanol had a higher sensitivity and linearity owning to the construction of additional conductive paths. The optimal conditions for realizing a high-performance pressure sensor are a multiwalled carbon nanotube mass ratio of 7% and a composite membrane thickness of 490 µm. The membrane achieves a high linear sensitivity of -57.07 kΩ∙kPa-1 and a linear fitting correlation coefficient of 98.78% in the 0.13~5.2 kPa pressure range corresponding to pulse detection. Clearly, this device has great potential for application in pulse detection.