Green Fluorescent Carbon Dots with Critically Controlled Surface States: Make Silk Shine via Feeding Silkworms.

Feeding silkworms with functional materials as additives to produce naturally modified silk is a facile, diverse, controllable, and environmentally friendly method with a low cost of time and investment. Among various additives, carbon dots (CDs) show unique advantages due to their excellent biocompatibility and fluorescence stability. Here, a new type of green fluorescent carbon dots (G-CDs) is synthesized with a high oil-water partition ratio of 147, a low isoelectric point of 5.16, an absolute quantum yield of 71%, and critically controlled surface states. After feeding with G-CDs, the silkworms weave light yellow cocoons whose green fluorescence is visible to the naked eye under UV light. The luminous silk is sewn onto the cloth to create striking patterns with beautiful fluorescence. Such G-CDs have no adverse effect on the survival rate and the life cycle of silkworms and enable their whole bodies to glow under UV light. Based on the strong fluorescence, chemical stability, and biological safety, G-CDs are found in the digestive tracts, silk glands, feces, cocoons, and even moth bodies. G-CDs accumulate in the posterior silk glands where fibroin protein is secreted, indicating its stronger combination with fibroin than sericin, which meets the requirements for practical applications.

Correction: A poly(thymine)-templated fluorescent copper nanoparticle hydrogel-based visual and portable strategy for an organophosphorus pesticide assay.

Correction for 'A poly(thymine)-templated fluorescent copper nanoparticle hydrogel-based visual and portable strategy for an organophosphorus pesticide assay' by Jihua Chen et al., Analyst, 2019, 144, 2423-2429, https://doi.org/10.1039/C9AN00017H.

Reusable carboxylesterase immobilized in ZIF for efficient degradation of chlorpyrifos in enviromental water.

The past few decades have witnessed biodegradation of pesticides as a significant method in remediation of the environment for its specificity, efficiency and biocompatibility. However, the tolerability and recyclability of the enzymes in pesticide degradation and the development of enzymes that biodegrad pesticides are still urgent problems to be solved so far. Herein, a novel hyper-thermostable and chlorpyrifos-hydrolyzing carboxylesterase EstC was immobilized by biomineralization using zeolitic imidazolate framework (ZIF), one of the metal-organic frameworks (MOFs) with highly diverse structure and porosity. Compared with free enzyme, EstC@ZIF with a cruciate flower-like morphology presented scarcely variation in catalytic efficiency and generally improved the tolerance to organic solvents or detergents. Furthermore, there was scarcely decrease in the catalytic efficiency of EstC@ZIF and it also showed good reusability with about 50% residual activity after 12 continuous uses. Notably, EstC@ZIF could be used in actual water environment with an excellent value of degradation rate of 90.27% in 120 min, and the degradation efficiency remained about 50% after 9 repetitions. The present strategy of immobilizing carboxylesterase to treat pesticide-contaminated water broadens the method of immobilized enzymes on MOFs, and envisions its recyclable applicability in globe environmental remediation.

Characterization of a carboxylesterase with hyper-thermostability and alkali-stability from Streptomyces lividans TK24.

A gene (estA', 804 bp) from Streptomyces lividans TK24 was artificially synthesized and successfully overexpressed as a 6His-tagged fusion protein in Escherichia coli. It encoded a carboxylesterase (EstA) that composed of 267 amino acids with a predicted molecular weight of 28.56 kDa. Multiple sequence alignment indicated that EstA has typical characteristics of esterases, including a catalytic triad (Ser93-Asp194-His224) and a conserved pentapeptide motif (Gly91-Leu92-Ser93-Met94-Gly95). Simultaneously, phylogenetic analysis indicated that EstA belongs to family VI. Biochemical characterization displayed its optimum enzyme activity was at 55 â„ƒ and pH 8.5. Additionally, EstA exhibited higher activity towards short carbon substrates and showed the outstanding catalytic efficiency for pNPA2 with kcat/Km of 2296.14 ± 10.35 s-1 mM-1. Notably, EstA has hyper-thermostability and good alkali stability. The activity of EstA did not change obviously when incubated at 50 and 100 â„ƒ for 337 and 1 h, independently. Besides, by incubating at 100 â„ƒ for 6 h, EstA remained about half of its initial activity. Moreover, EstA showed stability at pH ranging from 8.0 to 11.0, and about 90% residual enzyme activity was reserved by being treated at pH 8.0 or 9.0 for 80 h, especially. Such multiple features prepare EstA for a potential candidate in the field of biological catalysis of some industrial applications under harsh conditions.

Characterization of a novel hyper-thermostable and chlorpyrifos-hydrolyzing carboxylesterase EstC: A representative of the new esterase family XIX.

Carboxylesterases have widely been used in a series of industrial applications, especially, the detoxification of pesticide residues. In the present study, EstC, a novel carboxylesterase from Streptomyces lividans TK24, was successfully heterogeneously expressed, purified and characterized. Phylogenetic analysis showed that EstC can be assigned as the first member of a novel family XIX. Multiple sequence alignment indicated that EstC has highly conserved structural features, including a catalytic triad formed by Ser155, Asp248 and His278, as well as a canonical Gly-His-Ser-Ala-Gly pentapeptide. Biochemical characterization indicated that EstC exhibited maximal activity at pH 9.0 (Tris-HCl buffer) and 55 °C. It also showed higher activity towards short-chain substrates, with the highest activity for p-nitrophenyl acetate (pNPA2) (Km = 0.31 ± 0.02 mM, kcat/Km = 1923.35 ± 9.62 s-1 mM-1) compared to other pNP esters used in this experiment. Notably, EstC showed hyper-thermostability and good alkali stability. The activity of EstC had no significant changes when it was incubated under 55 °C for 100 h and reached half-life after incubation at 100 °C for 8 h. Beyond that, EstC also showed stability at pH ranging from 6.0 to 11.0 and about 90% residual activity still reserved after treatment at pH 8.0 or 9.0 for 26 h, especially. Furthermore, EstC had outstanding potential for bioremediation of chlorpyrifos-contaminated environment. The recombinant enzyme (0.5 U mL-1) could hydrolyze 79.89% chlorpyrifos (5 mg L-1) at 37 °C within 80 min. These properties will make EstC have a potential application value in various industrial productions and detoxification of chlorpyrifos residues.

A poly(thymine)-templated fluorescent copper nanoparticle hydrogel-based visual and portable strategy for an organophosphorus pesticide assay.

Since fluorescence assays with high sensitivity for organophosphorus pesticides (OPs) are urgently required to protect the ecosystem and prevent disease, an environmentally friendly and label-free fluorescent probe is desirable. Herein, a poly-thymine30 DNA-templated copper nanoparticle (poly T30-Cu NPs) hydrogel fluorescent probe was explored for the construction of an OPs sensing platform via tyrosinase (TYR) enzyme-controlled quenching. Initially, TYR can efficiently quench the fluorescence of poly T30-Cu NPs; however, when OPs are mixed with a certain amount of TYR, the fluorescence of poly T30-Cu NPs can be recovered. Based on this phenomenon, we designed a functionalized hydrogel based on poly T30-Cu NPs for portable and visible detection of OPs with high sensitivity and selectivity. This proposed fluorescent platform was demonstrated to enable rapid detection of OPs (paraoxon as the model analyte) and provide excellent sensitivity with a detection limit of 3.33 × 10-5 ng µL-1 and a linear range of 1.0 × 10-4-1.0 ng µL-1. The fluorescent probe does not require a sophisticated synthesis and labeling process; in addition, it is environmentally friendly because of the presence of a biotemplate of DNA and biocompatible copper. Moreover, the functional hydrogel combines the features of portability, visualization, fast signal response and environmental anti-interference that make the proposed strategy more feasible in complex practical detection.

Fluorometric methods for determination of H2O2, glucose and cholesterol by using MnO2 nanosheets modified with 5-carboxyfluorescein.

A fluorescent probe for H2O2 is described. It is composed of MnO2 nanosheets and 5-carboxyfluorescein and was characterized by fluorescence, transmission electron microscopy, ultraviolet-visible absorption spectra, energy dispersive X-ray and Fourier transform infrared spectroscopy. The probe, with fluorescence excitation/emission maxima at 490/518 nm, responds to H2O2 in the 1 to 200 µM concentration range and has a 0.33 µM detection limit. The probe was used in enzymatic assays for glucose and cholesterol by using the respective oxidases which produce H2O2. Responses are linear in the concentration range from 0.5 to 200 µM in case of glucose, and from 1 to 300 µM in case of cholesterol. The method was applied to quantify glucose and cholesterol in (spiked) serum samples. Graphical abstract Schematic presentation of the principle based on hydrogen peroxide-induced degradation of MnO2 nanosheet-FAM complex for detection of H2O2 (a), glucose and cholesterol (b).

Aprotinin Encapsulated Gold Nanoclusters: A Fluorescent Bioprobe with Dynamic Nuclear Targeting and Selective Detection of Trypsin and Heavy Metal.

Fluorescence imaging has currently emerged as one of the most frequently used noninvasive imaging technologies to selectively monitor biological processes in living systems. In past decades, gold nanoclusters (Au NCs) has received increasing attraction because of their intrinsic fluorescence and their inherent biocompatibility. As a stabilizing and reducing agent, an abundant, sustainable, and widely used polypeptide derived drug molecule, aprotinin (Ap), is selected for the synthesis of Au nanoclusters (Ap-Au NCs) due to characteristic bioactivity, excellent biocompatibility, biodegradability, and non-allergenic character. Herein, Ap encapsulated Au NCs with desirable red fluorescence was facilely produced for the first time, which were subsequently used for cell imaging and detection of various analytes. Much interestingly, dynamically subcellular targeting  from the cytoplasm to the nucleus in HeLa cells was observed. Besides, it has shown that, the selective and quantitative detection of trypsin has been established by using Ap-Au NCs. Finally, Ap-Au NCs were readily used for quantitative detection of mercury and copper. The photoluminescence of the Ap-Au NCs was quenched with the addition of the aforementioned analytes. This study not only  discusses a multifunctional nanomaterial  for cell imaging, dynamically nuclear targeting and biosensing, but also opens crucial insights on the integration of funtional biomolecule with metal nanoclusters intended for extensively biomedical applications.

Characterization of a novel highly thermostable esterase from the Gram-positive soil bacterium Streptomyces lividans TK64.

A novel esterase gene (estW) from soil bacterium Streptomyces lividans TK64 was successfully cloned using a pair of homologous primers. The estW gene encoded a protein (EstW) of 289 amino acid residues with a predicted molecular weight of 31.43 kDa. Sequence alignment revealed that EstW show relatively high levels of homology to other lipolytic enzymes characterized from Streptomyces and phylogenetic analysis suggested EstW belongs to the bacterial lipase/esterase family I. The estW gene was expressed at a high level in Escherichia coli and the recombinant enzyme was purified to homogeneity. The purified EstW was characterized via hydrolysis of various p-nitrophenyl esters and the best substrate was found to be p-nitrophenyl acetate (pNPA). Maximal activity of the recombinant protein was observed at pH 8.0 and 50 °C with pNPA as the substrate. The calculated activation energy (Ea ) of the esterase reaction was 9.12 kcal/mol. Half-life of EstW at 95 °C was approximately 12.5 H, making it the most thermostable esterase among all of the known lipolytic enzymes from Streptomyces, and the thermostability of EstW was similar to those of some enzymes characterized from the thermophilic bacteria. EstW exhibited relatively high tolerance to several detergents and required no cations for its maximal activity. The unique properties of EstW, namely its high thermostability and stability in the presence of organic solvents, may render it a potential candidate for industrial applications.

Bu Shen Tiao Chong recipe restores diminished ovary reserve through the BDNF pathway.

PURPOSE: The purpose of this study was to explore the molecular pathway of BSTCR (Bu Shen Tiao Chong recipe) in retrieving diminished ovary reserve (DOR). METHODS: The DOR model was established through injecting cyclophosphamide and the effect of BSTCR was examined under this background. RESULTS: BSTCR was shown to restore depleted brain-derived neurotrophic factor (BDNF), CDC2, cyclin B, GSH1, and P38 levels as well as impaired oocyte maturation and the higher apoptosis induced in DOR. BSTCR also enhances the response of oocytes to in vitro fertilization, with higher implantation rate, birth rate, and placenta weight. CONCLUSION: BSTCR might exert its beneficial role in oocyte maturation and restore DOR through regulating the BDNF pathway. And this pathway itself is probably through the consequence on several serum hormones such as FSH, E2, Inhibin B, etc.

Traditional Chinese medicine versus western medicine as used in China in the management of rheumatoid arthritis: a randomized, single-blind, 24-week study.

This study is designed to compare the efficacy and safety of traditional Chinese medicine (TCM) with western medicine (WM) in the management of rheumatoid arthritis (RA). This is a 24-week, randomized, multicenter, single-blind study comparing TCM with WM (as used in China) carried out between June 2002 and December 2004 in nine research centers in China, involving 489 patients. Patients were randomized to receive TCM (n = 247), MTX and SSZ (n = 242). MTX was started at a dose of 5 mg to a final dose of 7.5-15 mg weekly. The maintenance dose was 2.5-7.5 mg weekly. The starting dose of SSZ was 0.25 g bid, increasing by 0.25 g a day once a week to a final dose of 0.5-1 g qid. The maintenance dose was 0.5 g tid to qid. Primary end point was the proportion of patients with response according to the American College of Rheumatology 20 % improvement criteria (ACR20) at weeks 24. At 24 weeks, ACR20 responses were 53.0 % in TCM group and 66.5 % in WM group, (P < 0.001) at 24 weeks. ACR 50 responses were 31.6 % of TCM group and 42.6 % in WM group, (P = 0.01). ACR70 responses were 12.6 % in TCM group and 17.4 % in WM group, (P = 0.14). Side effects were observed more frequently in WM group. In this study, ACR20, ACR50 responses at 24 weeks were significantly better in the WM treated group, by intention to treat (ITT) and per protocol analysis. The ACR 70 response showed no significant difference between the two groups. TCM, while effective in treating RA, appears to be less effective than WM in controlling symptoms, but TCM is associated with fewer side effects.

Creative art therapy for postpartum depression： A systematic review and meta-analysis.

OBJECTIVE: This study aims to ascertain the effectiveness of creative art therapy (CAT) in alleviating symptoms of postpartum depression (PPD). METHODS: A systematic review of all randomized controlled trials of CAT for PPD was conducted. Eight bibliographic databases, namely, PubMed, The Cochrane Library, Embase, Web of Science, CNKI, Wanfang Database, VIP Database, and China Biomedical Literature Database were searched digitally, while Google Scholar database was searched manually for a comprehensive literature search. The search period is from the establishment of the database to May 2024. Literature screening and data extraction were conducted independently by two researchers, and the risk of bias in the included studies was evaluated. Finally, RevMan5.3 software and STATA 15.1 software were used for meta-analysis. RESULTS: Twelve studies, including 1633 patients, were included in this review. The results of our meta-analysis revealed that the intervention group was significantly better than the control group in depression [SMD = -0.882, 95 % CI: -1.256 to -0.508, P ＜ 0.001][WMD = 0.680, 95 % CI: 0.407-0.953, P ＜ 0.001], anxiety [SMD = -0.712, 95 % CI: -1.405 to -0.019, P = 0.044], and personal state [WMD = -5.180, 95 % CI: -5.869 to -4.491, P ＜ 0.001][SMD = 0.388, 95 % CI: 0.132-0.643, P = 0.003], and the difference was statistically significant. Sensitivity analysis revealed that the above results were stable. CONCLUSION: CAT (music and creative games) was found to be effective in relieving depression, anxiety, and personal state in patients with PPD. Though CAT appears to be worthy of clinical application, more high-quality and large-sample studies are required to explore various aspects in the current context.

Characterization of a novel carboxylesterase from Streptomyces lividans TK24 and site-directed mutagenesis for its thermostability.

As an industrial enzyme that catalyzes the formation and cleavage of ester bonds, carboxylesterase has attracted attention in fine chemistry, pharmaceutical, biological energy and bioremediation fields. However, the weak thermostability limits their further developments in industrial applications. In this work, a novel carboxylesterase (EstF) from Streptomyces lividans TK24, belonging to family XVII, was acquired by successfully heterologous expressed and biochemically identified. The EstF exhibited optimal activity at 55 °C, pH 9.0 and excellent catalytic performances (Km = 0.263 mM, kcat/Km = 562.3 s-1 mM-1 for p-nitrophenyl acetate (pNPA2) hydrolysis). Besides, the EstF presented exceptionally high thermostability with a half-life of 387.23 h at 55 °C and 2.86 h at 100 °C. Furthermore, the EstF was modified to obtain EstFP144G using the site-directed mutation technique to investigate the effect of single glycine on thermostability. Remarkably, the mutant EstFP144G displayed a 5.10-fold increase of half-life at 100 °C versus wild-type without affecting catalytic performance. Structural analysis implied that the glycine introduction could release a steric strain and induce cooperative effects between distal residues to increase the thermostability. Therefore, the thermostable EstF and EstFP144G with prominently catalytic characteristics have potential industrial applications and the introduction of a single glycine strategy opens up alternative avenues for the thermostability engineering of other enzymes.

The correlation between menstrual characteristics and fertility in women of reproductive age: a systematic review and meta-analysis.

IMPORTANCE: Menstruation serves as an indicator of women's reproductive well-being and plays a pivotal role in their fertility; nevertheless, there remains an ongoing debate regarding the epidemiological evidence linking menstrual characteristics as well as fertility. OBJECTIVE: To explore the correlation between menstrual characteristics and fertility in women of reproductive age. DATA SOURCES: A comprehensive literature search was conducted using PubMed, Embase, Web of Science, and Cochrane libraries to identify research articles published up until February 9, 2024. STUDY SELECTION AND SYNTHESIS: We included all studies in which the relationship between menstrual characteristics and pregnancy rates among women of reproductive age was investigated. We excluded studies involving the administration of oral contraceptives, the application of assisted reproductive technologies, and individuals with a documented history of infertility or partners with a known history of infertility. MAIN OUTCOME MEASURE(S): Clinical pregnancy and miscarriage. RESULT(S): This meta-analysis was composed of nine studies involving a total of 399,966 women, and the evidential quality derived from these studies was deemed to be high with a low risk of bias. Compared with a normal menstrual cycle length (25-32 days), the impact of a short (<25 days) or long (>32 days) menstrual cycle on a woman's pregnancy was relatively insignificant ([odds ratio {OR}, 0.81; 95% confidence interval {CI}, 0.65-1.01; I2, 68%]; [OR, 0.89; 95% CI, 0.75-1.06; I2, 60%], respectively); however, a change in cycle length may increase the risk of miscarriage ([relative risk, 1.87; 95% CI, 1.11-3.15; I2, 0]; [relative risk, 1.66; 95% CI, 1.07, 2.57; I2, 43%], respectively). In comparison to women experiencing menarche at a typical age (12-14 years), those with a late age at menarche (>14 years) exhibited a decreased likelihood of pregnancy (OR, 0.92; 95% CI, 0.91-0.93; I2, 0%); and compared with women experiencing a normal duration of menstrual bleeding (4-7 days), those with a short duration of menstrual bleeding (<4 days) exhibited reduced fertility potential (OR, 0.86; 95% CI, 0.84-0.88; I2, 29%). CONCLUSION(S): Short and long menstrual cycle lengths may elevate women's susceptibility to spontaneous abortion, whereas late age at menarche as well as short duration of menstrual bleeding appear to be linked to diminished fertility among women of reproductive age. CLINICAL TRIAL REGISTRATION: PROSPERO CRD42023487458 (9 December 2023).

Dual-functional cellulase-mediated gold nanoclusters for ascorbic acid detection and fluorescence bacterial imaging.

Protein-protected metal nanomaterials are becoming the most promising fluorescent nanomaterials for biosensing, bioimaging, and therapeutic applications due to their obvious fluorescent molecular properties, favorable biocompatibility and excellent physicochemical properties. Herein, we pioneeringly prepared a cellulase protected fluorescent gold nanoclusters (Cel-Au NCs) exhibiting red fluorescence under the excitation wavelength of 560 nm via a facile and green one-step method. Based on the fluorescence turn-off mechanism, the Cel-Au NCs were used as a biosensor for specificity determination of ascorbic acid (AA) at the emission of 680 nm, which exhibited satisfactory linearity over the range of 10-400 µM and the detection limit of 2.5 µM. Further, the actual sample application of the Au NCs was successfully established by evaluating AA in serum with good recoveries of 98.76%-104.83%. Additionally, the bacteria, including gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and gram-negative bacteria (Escherichia coli), were obviously stained by Cel-Au NCs with strong red emission. Thereby, as dual-functional nanoclusters, the prepared Cel-Au NCs have been proven to be an excellent fluorescent bioprobe for the detection of AA and bacterial labeling in medical diagnosis and human health maintenance.

Electrochemical amplified detection of Hg2+ based on the supersandwich DNA structure.

A supersandwich DNA structure was fabricated and used for the amplified detection of Hg(2+).

Acupuncture for Female Infertility: Discussion on Action Mechanism and Application.

A higher incidence of female infertility has been reported with an unexpectedly early appearance in recent years. The female infertility treatment and application of assisted reproductive technology have recently gained immense interest from scientists. Many studies have discussed the beneficial effects of acupuncture on female infertility. With advancements in science and medical technology, acupuncture-related research has increased in investigating its effectiveness in treating female infertility. This review focuses on a compilation of research in recent years on acupuncture for female infertility treatment and the exploration of the underlying mechanism. For this purpose, literature was searched using various search engines like PubMed, Web of Science, and Google Scholar. The search was refined by only focusing on recent studies on acupuncture effectiveness and mechanism in female infertility and evaluating pregnancy outcomes.

Recent progress of Bioinspired Hydrogel-based delivery system for endometrial repair.

Endometrial injury is the main fact leading to infertility. Current treatments of endometrial injury present many problems, such as unable to achieve desired effects due to low retention and the inherent potential risk of injury. Besides, it is important to the development of bioinspired material that can mimic the natural tissue and possess native tissue topography. Hydrogel is a kind of bioinspired superhydrophilic materials with unique characteristics, such as excellent biocompatibility, biodegradability, porosity, swelling, and cross-linkage. These unique physiochemical properties of bioinspired hydrogels enable their promising application as novel delivery platform and alternative therapies for endometrial injury. In this mini review, we summarize the recent advances in bioinispred hydrogel-based delivery system for endometrial repair, including as a post-operative physical barrier and therapeutic delivery system. In addition, present status, limitations, and future perspectives are also discussed.

Excellent catalytic properties of luminescent Cu@Cu2S nanozymes and their antibacterial applications.

Luminescent Cu@Cu2S nanozymes have been prepared by a one-pot method, displaying high peroxidase-like and oxidase-like activity. Fluorescence images show that these nanozymes adhere to the surface of the bacterial cell and scanning electron microscopy reveals that the nanomaterials cause folding and collapse of the bacterial surface, resulting in bacterial death.

Expression and identification of a thermostable malate dehydrogenase from multicellular prokaryote Streptomyces avermitilis MA-4680.

A malate dehydrogenase (MDH) from Streptomyces avermitilis MA-4680 (SaMDH) has been expressed and purified as a fusion protein. The molecular mass of SaMDH is about 35 kDa determined by SDS-PAGE. The recombinant SaMDH has a maximum activity at pH 8.0. The enzyme shows the optimal temperature around 42 °C and displays a half-life (t(1/2)) of 160 min at 50°C which is more thermostable than reported MDHs from most bacteria and fungi. The k(cat) value of SaMDH is about 240-fold of that for malate oxidation. In addition, the k(cat)/K(m) ratio shows that SaMDH has about 1,246-fold preference for oxaloacetate (OAA) reduction over L-malate oxidation. The recombinant SaMDH may also use NADPH as a cofactor although it is a highly NAD(H)-specific enzyme. There was no activity detected when malate and NADP(+) were used as substrates. Substrate inhibition studies show that SaMDH activity is strongly inhibited by excess OAA with NADH, but is not sensitive to excess L-malate. Enzymatic activity is enhanced by the addition of Na(+), NH(4)(+), Ca(2+), Cu(2+) and Mg(2+) and inhibited by addition of Hg(2+) and Zn(2+). MDH is widely used in coenzyme regeneration, antigen immunoassays and bioreactors. The enzymatic analysis could provide the important basic knowledge for its utilizations.