Loss of PKC mu function induces cytoskeletal defects in mouse oocyte meiosis.

Cytoskeleton which includes microtubule and actin filaments plays important roles during mammalian oocyte maturation. In the present study, we showed that protein kinase C mu (PKC mu) was one potential key molecule which affected cytoskeleton dynamics in mouse oocytes. Our results showed that PKC mu expressed and localized at the poles of the spindle during oocyte maturation, and PKC mu expression reduced in the oocytes from 6-month-old mice or 24 hr in vitro culture. We knocked down the expression of PKC mu in oocytes using morpholino injection to explore the relationship between PKC mu and subcellular structure defects. The loss of PKC mu reduced oocyte maturation competence, showing with decreased polar body extrusion rate and increased rate of symmetric division. Further analysis indicated that PKC mu decrease caused the spindle organization defects, and this could be confirmed by the decreased tubulin acetylation level. Moreover, we found that PKC mu affected the phosphorylation level of cofilin for actin assembly, which further affected cytoplasmic actin distribution and spindle positioning. In summary, our data indicated that PKC mu is one key factor for oocyte maturation through its roles on the spindle organization and actin filament distribution.

The small GTPase RhoA regulates the LIMK1/2-cofilin pathway to modulate cytoskeletal dynamics in oocyte meiosis.

LIM kinases (LIMK1/2) are LIM domain-containing serine/threonine/tyrosine kinases that mediate multiple cellular processes in mitosis. In the present study, we explored the functional roles and potential signaling pathway of LIMK1/2 during mouse oocyte meiosis. Disruption of LIMK1/2 activity and expression significantly decreased oocyte polar body extrusion. Live-cell imaging revealed that spindle migration was disturbed after both LIMK1 and LIMK2 knock down, and this might be due to aberrant distribution of actin filaments in the oocyte cytoplasm and cortex. Meanwhile, our results demonstrated that the function of LIMK1 and LIMK2 in actin assembly was related to cofilin phosphorylation levels. In addition, disruption of LIMK1/2 activity significantly increased the percentage of oocytes with abnormal spindle morphologies, which was confirmed by the abnormal p-MAPK localization. We further, explored the upstream molecules of LIMK1/2, and we found that after depletion of ROCK, phosphorylation of LIMK1/2 and cofilin were significantly decreased. Moreover, RhoA inhibition caused the decreased expression of ROCK, p-LIMK1/2, and cofilin. In summary, our results indicated that the small GTPase RhoA regulated LIMK1/2-cofilin to modulate cytoskeletal dynamics during mouse oocyte meiosis.

Co9 S8 Nanoparticles-Embedded N/S-Codoped Carbon Nanofibers Derived from Metal-Organic Framework-Wrapped CdS Nanowires for Efficient Oxygen Evolution Reaction.

Metal-organic frameworks (MOFs) with tunable compositions and morphologies are recognized as efficient self-sacrificial templates to achieve function-oriented nanostructured materials. Moreover, it is urgently needed to develop highly efficient noble metal-free oxygen evolution reaction (OER) electrocatalysts to accelerate the development of overall water splitting green energy conversion systems. Herein, a facile and cost-efficient strategy to synthesize Co9 S8 nanoparticles-embedded N/S-codoped carbon nanofibers (Co9 S8 /NSCNFs) as highly active OER catalyst is developed. The hybrid precursor of core-shell ZIF-wrapped CdS nanowires is first prepared and then leads to the formation of uniformly dispersed Co9 S8 /N, S-codoped carbon nanocomposites through a one-step calcination reaction. The optimal Co9 S8 /NSCNFs-850 is demonstrated to possess excellent electrocatalytic performance for OER in 1.0 m KOH solution, affording a low overpotential of 302 mV to reach the current density of 10 mA cm-2 , a small Tafel slope of 54 mV dec-1 , and superior long-term stability for 1000 cyclic voltammetry cycles. The favorable results raise a concept of exploring more MOF-based nanohybrids as precursors to induce the synthesis of novel porous nanomaterials as non-noble-metal electrocatalysts for sustainable energy conversion.

Multishelled Nix Co3-x O4 Hollow Microspheres Derived from Bimetal-Organic Frameworks as Anode Materials for High-Performance Lithium-Ion Batteries.

Metal-organic frameworks (MOFs) featuring versatile topological architectures are considered to be efficient self-sacrificial templates to achieve mesoporous nanostructured materials. A facile and cost-efficient strategy is developed to scalably fabricate binary metal oxides with complex hollow interior structures and tunable compositions. Bimetal-organic frameworks of Ni-Co-BTC solid microspheres with diverse Ni/Co ratios are readily prepared by solvothermal method to induce the Ni x Co3-x O4 multishelled hollow microspheres through a morphology-inherited annealing treatment. The obtained mixed metal oxides are demonstrated to be composed of nanometer-sized subunits in the shells and large void spaces left between adjacent shells. When evaluated as anode materials for lithium-ion batteries, Ni x Co3-x O4 -0.1 multishelled hollow microspheres deliver a high reversible capacity of 1109.8 mAh g-1 after 100 cycles at a current density of 100 mA g-1 with an excellent high-rate capability. Appropriate capacities of 832 and 673 mAh g-1 could also be retained after 300 cycles at large currents of 1 and 2 A g-1 , respectively. These prominent electrochemical properties raise a concept of synthesizing MOFs-derived mixed metal oxides with multishelled hollow structures for progressive lithium-ion batteries.

A Metal-Organic Framework/DNA Hybrid System as a Novel Fluorescent Biosensor for Mercury(II) Ion Detection.

Mercury(II) ions have emerged as a widespread environmental hazard in recent decades. Despite different kinds of detection methods reported to sense Hg(2+) , it still remains a challenging task to develop new sensing molecules to replenish the fluorescence-based apparatus for Hg(2+) detection. This communication demonstrates a novel fluorescent sensor using UiO-66-NH2 and a T-rich FAM-labeled ssDNA as a hybrid system to detect Hg(2+) sensitively and selectively. To the best of our knowledge, it has rarely been reported that a MOF is utilized as the biosensing platform for Hg(2+) assay.

[Egg Freshness Detection Based on Hyper-Spectra].

This research collected the transmission hyper-spectral data of eggs with hyper-spectral imager. Haugh unit value was used as freshness norm. With the help of MATLAB and SAS software combined with stechiometry method, the hyper-spectral data of sample eggs was analyzed and processed. The prediction model of egg freshness was established based on hyper-spectral technology. The research chose the band range from 500 to 1 000 nm as sensitive band. The hyper-spectral data of abnormal samples were removed by using mahalanobis distance. Differential correction was done on hyper-spectral data. After the comparison, there was a high linearity between the second-order differential data of hyper-spectra and haugh unit value. Therefore, this paper conducted a further research on the second-order differential data of hyper-spectra. And it was treated with wavelet denoising, smoothing and standardizing. This paper chose the newly proposed CARS variable selection method to do dimensionality reduction on hyper-spectral data. And thirty-two characteristic parameters were extracted. They were used to establish partial least square prediction model based on all band and multiple regression model based on characteristic parameters on white shell eggs. The correlation coefficients of white shell eggs were 0.88 and 0.93 respectively, and the corresponding mean square errors being 7.565 and 6.44. Inspections were conducted on PLS prediction model based on all band hyper-spectral second-order differential and multiple regression model based on characteristic parameters by using eggs of validation set. The accuracy rates of these two models to discriminate white shell eggs' freshness and non-freshness were 100% and 88% respectively.

Encapsulation of Ln(III) Ions/Dyes within a Microporous Anionic MOF by Post-synthetic Ionic Exchange Serving as a Ln(III) Ion Probe and Two-Color Luminescent Sensors.

A new anionic framework {[Me2NH2]0.125[In0.125(H2L)0.25]⋅xDMF}n (1) with one-dimensional (1D) channels along the c axis of about 13.06×13.06 Å(2), was solvothermally synthesized and well characterized. Post-synthetic cation exchange of 1 with Eu(3+), Tb(3+), Dy(3+), Sm(3+) afforded lanthanide(III)-loaded materials, Ln(3+)@1, with different luminescent behavior, indicating that compound 1 could be used as a potential luminescent probe toward different lanthanide(III) ions. Additionally, compound 1 exhibits selective adsorption ability toward cationic dyes. Moreover, the RhB@1 realized the probing of different organic solvent molecules by tuning the energy transfer efficiency between two different emissions, especially for sensing DMF. This work highlights the practical application of luminescent guest@MOFs as sensors, and it paves the way toward other one/multi-color luminescent host-guest systems by rational selection of MOF hosts and guest chromophores with suitable emissive colors and energy levels.

Preparation and microscopy examination of alginate-poly-L-lysine-alginate microcapsules.

Ca-alginate-poly-l-lysine-alginate (APA-Ca) and Ba-alginate-poly-l-lysine-alginate (APA-Ba) microcapsules were prepared and their thickness and surface were examined by light microscopy and scanning electron microscopy. Specifically, light microscopy with frozen section was used to visualize and quantify the thickness of APA membrane, and monitor temporal changes in the thickness of microcapsules during a month long culture in vitro. The section graph of APA microcapsule represents the accurate measurement of layer thickness of APA-Ca with diameter 900 ± 100 and 500 ± 100 µm at 6.01 ± 1.02 and 9.54 ± 2.42 µm (p < 0.05), and layer thickness of APA-Ba with diameter 900 ± 100 and 500 ± 100 µm at 5.47 ± 0.90 and 8.21 ± 1.97 µm (p < 0.05), regardless of the alginate composition used to generate the microcapsules. The microcapsule was stable during the culture for 30 days in vitro. Field emission scanning electron microscopy with freeze drying method was used to detect the surface and thickness of dried microcapsules. From the results, the outer surface of APA-Ca and APA-Ba membrane were smooth and dense, the film thickness of the APA-Ca was about 450-690 nm, while the APA-Ba was approximately 335 nm. In vivo experiment, little significant difference was seen in the change of film thickness of microcapsules in intrapertioneal site for 30 days after transplantation (p > 0.05), except that the recovery of APA-Ba was higher than the APA-Ca microcapsules. The paper showed an easy method to prepare APA-Ca and APA-Ba, and examine their thickness and surface, which could be utilized to study other types of microcapsules.

Clinical guideline on magnetically controlled capsule gastroscopy (2021 edition).

With the development and generalization of endoscopic technology and screening, clinical application of magnetically controlled capsule gastroscopy (MCCG) has been increasing. In recent years, various types of MCCG are used globally. Therefore, establishing relevant guidelines on MCCG is of great significance. The current guidelines containing 23 statements were established based on clinical evidence and expert opinions, mainly focus on aspects including definition and diagnostic accuracy, application population, technical optimization, inspection process, and quality control of MCCG. The level of evidence and strength of recommendations were evaluated. The guidelines are expected to guide the standardized application and scientific innovation of MCCG for the reference of clinicians.

Identification and characterization of a novel fumarase gene by metagenome expression cloning from marine microorganisms.

BACKGROUND: Fumarase catalyzes the reversible hydration of fumarate to L-malate and is a key enzyme in the tricarboxylic acid (TCA) cycle and in amino acid metabolism. Fumarase is also used for the industrial production of L-malate from the substrate fumarate. Thermostable and high-activity fumarases from organisms that inhabit extreme environments may have great potential in industry, biotechnology, and basic research. The marine environment is highly complex and considered one of the main reservoirs of microbial diversity on the planet. However, most of the microorganisms are inaccessible in nature and are not easily cultivated in the laboratory. Metagenomic approaches provide a powerful tool to isolate and identify enzymes with novel biocatalytic activities for various biotechnological applications. RESULTS: A plasmid metagenomic library was constructed from uncultivated marine microorganisms within marine water samples. Through sequence-based screening of the DNA library, a gene encoding a novel fumarase (named FumF) was isolated. Amino acid sequence analysis revealed that the FumF protein shared the greatest homology with Class II fumarate hydratases from Bacteroides sp. 2_1_33B and Parabacteroides distasonis ATCC 8503 (26% identical and 43% similar). The putative fumarase gene was subcloned into pETBlue-2 vector and expressed in E. coli BL21(DE3)pLysS. The recombinant protein was purified to homogeneity. Functional characterization by high performance liquid chromatography confirmed that the recombinant FumF protein catalyzed the hydration of fumarate to form L-malate. The maximum activity for FumF protein occurred at pH 8.5 and 55°C in 5 mM Mg(2+). The enzyme showed higher affinity and catalytic efficiency under optimal reaction conditions: K(m) = 0.48 mM, V(max) = 827 µM/min/mg, and k(cat)/K(m) = 1900 mM/s. CONCLUSIONS: We isolated a novel fumarase gene, fumF, from a sequence-based screen of a plasmid metagenomic library from uncultivated marine microorganisms. The properties of FumF protein may be ideal for the industrial production of L-malate under higher temperature conditions. The identification of FumF underscores the potential of marine metagenome screening for novel biomolecules.

Exposure to podophyllotoxin inhibits oocyte meiosis by disturbing meiotic spindle formation.

Podophyllotoxin is used as medical cream which is widely applied to genital warts and molluscum contagiosum. Although previous study showed that podophyllotoxin had minimal toxicity, it was forbidden to use during pregnancy since it might be toxic to the embryos. In present study we used mouse as the model and tried to examine whether podophyllotoxin exposure was toxic to oocyte maturation, which further affected embryo development. Our results showed that podophyllotoxin exposure inhibited mouse oocyte maturation, showing with the failure of polar body extrusion, and the inhibitory effects of podophyllotoxin on oocytes was dose-depended. Further studies showed that the meiotic spindle formation was disturbed, the chromosomes were misaligned and the fluorescence signal of microtubule was decreased, indicating that podophyllotoxin may affect microtubule dynamics for spindle organization. Moreover, the oocytes which reached metaphase II under podophyllotoxin exposure also showed aberrant spindle morphology and chromosome misalignment, and the embryos generated from these oocytes showed low developmental competence. We also found that the localization of p44/42 MAPK and gamma-tubulin was disrupted, which further confirmed the effects of podophyllotoxin on meiotic spindle formation. In all, our results indicated that podophyllotoxin exposure could affect mouse oocyte maturation by disturbing microtubule dynamics and meiotic spindle formation.

Involvement of LIMK1/2 in actin assembly during mouse embryo development.

LIMKs (LIMK1 and LIMK2) are serine/threonine protein kinases that involve in various cellular activities such as cell migration, morphogenesis and cytokinesis. However, its roles during mammalian early embryo development are still unclear. In the present study, we disrupted LIMK1/2 activity to explore the functions of LIMK1/2 during mouse early embryo development. We found that p-LIMK1/2 mainly located at the cortex of each blastomeres from 2-cell to 8-cell stage, and p-LIMK1/2 also expressed at morula and blastocyst stage in mouse embryos. Inhibition of LIMK1/2 activity by LIMKi 3 (BMS-5) at the zygote stage caused the failure of embryo early cleavage, and the disruption of LIMK1/2 activity at 8-cell stage caused the defects of embryo compaction and blastocyst formation. Fluorescence staining and intensity analysis results demonstrated that the inhibition of LIMK1/2 activity caused aberrant cortex actin expression and the decrease of phosphorylated cofilin in mouse embryos. Taken together, we identified LIMK1/2 as an important regulator for cofilin phosphorylation and actin assembly during mouse early embryo development.

A Temperature-Responsive Smart Europium Metal-Organic Framework Switch for Reversible Capture and Release of Intrinsic Eu3+ Ions.

Stimuli-responsive structural transformations are emerging as a scaffold to develop a charming class of smart materials. A EuL metal-organic framework (MOF) undergoes a reversible temperature-stimulated single-crystal to single-crystal transformation, showing a specific behavior of fast capture/release of free Eu3+ in the channels at low and room temperatures. At room temperature, compound 1a is obtained with one free carboxylate group severing as further hook, featuring one-dimensional square channels filled with intrinsic free europium ions. Trigged by lowering the ambient temperature, 1b is gained. In 1b, the intrinsic free europium ions can be fast captured by the carboxylate-hooks anchored in the framework, resulting in the structural change and its channel distortion. To the best of our knowledge, this is the first report of such a rapid and reversible switch stemming from dynamic control between noncovalent and covalent Eu-ligand interactions. Utilizing EuL MOF to detect highly explosive 2,4,6-trinitrophenol at room temperature and low temperature provides a glimpse into the potential of this material in fluorescence sensors.

Assembly of three coordination polymers based on a sulfonic-carboxylic ligand showing high proton conductivity.

Three new coordination polymers (CPs)/metal-organic frameworks (MOFs) with different structures have been synthesized using 4,8-disulfonyl-2,6-naphthalenedicarboxylic acid (H4L) and metal ions, Cu(2+), Ca(2+) and Cd(2+). The Cu compound features a one-dimensional chain structure, further extending into a 2D layer network through H-bond interactions. Both the Ca and Cd compounds show 3D frameworks with (4,4)-connected PtS-type topology and (3,6)-connected bct-type topology, respectively. These CPs/MOFs all exhibit proton conduction behavior, especially for the Cu compound with a proton conductivity of 3.46 × 10(-3) S cm(-1) at 368 K and 95% relative humidity (RH). Additionally, the activation energy (Ea) has also been investigated to deeply understand the proton-conduction mechanism.

A tetranuclear copper cluster-based MOF with sulfonate-carboxylate ligands exhibiting high proton conduction properties.

A tetranuclear copper cluster-based MOF with sulfonate-carboxylate ligands has been synthesized. It possesses one-dimensional irregular channels lined with sulfonate, carboxylate, and DMF molecules, which show a high proton conductivity of 7.4 × 10(-4) S cm(-1) at 95 °C and 95% relative humidity.

Gastric cancer differentiation using Fourier transform near-infrared spectroscopy with unsupervised pattern recognition.

The manuscript has investigated the application of near-infrared (NIR) spectroscopy for differentiation gastric cancer. The 90 spectra from cancerous and normal tissues were collected from a total of 30 surgical specimens using Fourier transform near-infrared spectroscopy (FT-NIR) equipped with a fiber-optic probe. Major spectral differences were observed in the CH-stretching second overtone (9000-7000 cm(-1)), CH-stretching first overtone (6000-5200 cm(-1)), and CH-stretching combination (4500-4000 cm(-1)) regions. By use of unsupervised pattern recognition, such as principal component analysis (PCA) and cluster analysis (CA), all spectra were classified into cancerous and normal tissue groups with accuracy up to 81.1%. The sensitivity and specificity was 100% and 68.2%, respectively. These present results indicate that CH-stretching first, combination band and second overtone regions can serve as diagnostic markers for gastric cancer.

Biochemical characterization of two novel ß-glucosidase genes by metagenome expression cloning.

Two novel ß-glucosidase genes designated as bgl1D and bgl1E, which encode 172- and 151-aa peptides, respectively, were cloned by function-based screening of a metagenomic library from uncultured soil microorganisms. Sequence analyses indicated that Bgl1D and Bgl1E exhibited lower similarities with some putative ß-glucosidases. Functional characterization through high-performance liquid chromatography demonstrated that purified recombinant Bgl1D and Bgl1E proteins hydrolyzed D-glucosyl-ß-(1-4)-D-glucose to glucose. Using p-nitrophenyl-ß-D-glucoside as substrate, K(m) was 0.54 and 2.11 mM, and k(cat)/K(m) was 1489 and 787 mM(-1) min(-1) for Bgl1D and Bgl1E, respectively. The optimum pH and temperature for Bgl1D was pH 10.0 and 30°C, while the optimum values for Bgl1E were pH 10.0 and 25°C. Bgl1D exhibited habitat-specific characteristics, including higher activity in lower temperature and at high concentrations of AlCl(3) and LiCl. Bgl1D also displayed remarkable activity across a broad pH range (5.5-10.5), making it a potential candidate for industrial applications.

[Analysis on laboratory and clinical characteristics in 65 cases of myelodysplastic syndrome].

The aim of this study was to gain more insight into the understanding of myelodysplastic syndrome in the clinical and laboratory features. The clinical data of 65 patients with MDS were reviewed and analysed. According to FAB criteria, 65 patients were classified as follows: 27 patients with RA, 1 patient with RAS, 33 patients with RAEB, 3 patients with RAEB-T, and 1 patient with CMML. The median age of them was 66 years old (range 19-89 years), and 6 patients had a history of toxic exposure (secondary MDS). The bone marrow smears, bone marrow biopsy and cytogenetic examinations were performed in this study. The results showed that dysplasia was found in 64 patients examined with bone marrow smears (98.5%), among them trilineage dysplasia in 21 patients (32.3%), bilineage dysplasia in 33 patients (50.8%), only erythroid dysplasia in 8 cases (12.3%) and 2 patients (3.1%) only with myeloid dysplasia. The bone marrow biopsy was performed in 38 patients, abnormal localization of immature precursor (ALIP) occurred in 6 cases. 29 patients had abnormal karyotypes, accounting for 59.2% of the 49 patients subjected cytogenetic examination. The abnormal chromosome was the major cytogenetic abnormality, which occurred more often in secondary MDS and the patients with RAEB or RAEB-T. Among the 49 patients who had received cytogenetic examination, 15 patients transformed into AML with the incidence of 30.61%, but only 3 out of 20 patients in the group of normal chromosome transformed into AML (15%), while 12 out of 29 patients in the group of abnormal karyotypes transformed into AML (41.4%). The median time of following up was 35 months (range 2 - 106 months). The median survival time was 26.8 months and 8 months in the patients with normal karyotype and chromosome aberrations respectively. In conclusion, the incidence of MDS in our country is younger than that in Western countries, the rate of abnormal chromosome in high risk MDS is higher than that in low risk MDS. Meanwhile, those who have the change of chromosome are related to the transformation of MDS into AML and have shorter survival time than those MDS patients with normal karyotypes.