Novel High-Performance Glyoxylate Derivative-Based Photoinitiators for Free Radical Photopolymerization and 3D Printing with Visible LED.

Investigations concerning the glyoxylate moiety as a photocleavable functional group for visible light photoinitiators, particularly in the initiation of free radical photopolymerization remain limited. This study introduces nine innovative carbazole-based ethyl glyoxylate derivatives (CEGs), which are synthesized and found to exhibit excellent photoinitiation abilities as monocomponent photoinitiating systems. Notably, these structures demonstrate robust absorption in the near-UV/visible range, surpassing the commercial photoinitiators. Moreover, the newly developed glyoxylate derivatives show higher acrylate function conversions compared to a benchmark photoinitiator (MBF) in free radical photopolymerization. Elucidation of the photoinitiation mechanism of CEGs is achieved through a comprehensive analysis involving the decarboxylation reaction and electron spin resonance spin trapping. Furthermore, their practical utility is confirmed during direct laser writing and 3D printing processes, enabling the successful fabrication of 3D printed objects. This study introduces pioneering concepts and effective strategies in the molecular design of novel photoinitiators, showcasing their potential for highly advantageous applications in 3D printing.

Ultrafast Sunlight-Induced Polymerization: Unveiling 2-Phenylnaphtho[2,3-d]Thiazole-4,9-dione as a Unique Scaffold for High-Speed and Precision 3D Printing.

A series of 15 dyes based on the 2-phenylnaphtho[2,3-d]thiazole-4,9-dione scaffold and 1 compound based on the 2,3-diphenyl-1,2,3,4-tetrahydrobenzo[g]quinoxaline-5,10-dione scaffold are studied as photoinitiators. These compounds are used in two- and three-component high-performance photoinitiating systems for the free radical polymerization of trimethylolpropane triacrylate (TMPTA) and polyethylene glycol diacrylate (PEGDA) under sunlight. Remarkably, the conversion of TMPTA can reach ≈60% within 20 s, while PEGDA attains a 96% conversion within 90 s. To delve into the intricate chemical mechanisms governing the polymerization, an array of analytical techniques is employed. Specifically, UV-vis absorption and fluorescence spectroscopy, steady-state photolysis, stability experiments, fluorescence quenching experiments, cyclic voltammetry, and electron spin resonance spin trapping (ESR-ST) experiments, collectively contribute to a comprehensive understanding of the photochemical mechanisms. Photoinitiation capacities of these systems are determined using real-time Fourier transformed infrared spectroscopy (RT-FTIR). Of particular interest is the revelation that, owing to the superior initiation ability of these dyes, high-resolution 3D patterns can be manufactured by direct laser write (DLW) technology and 3D printing. This underscores the efficient initiation of free radical polymerization processes by the newly developed dyes under both artificial and natural light sources, presenting an avenue for energy-saving, and environmentally friendly polymerization conditions.

Structural Functions of 3D-Printed Polymer Scaffolds in Regulating Cell Fates and Behaviors for Repairing Bone and Nerve Injuries.

Tissue repair and regeneration, such as bone and nerve restoration, face significant challenges due to strict regulations within the immune microenvironment, stem cell differentiation, and key cell behaviors. The development of 3D scaffolds is identified as a promising approach to address these issues via the efficiently structural regulations on cell fates and behaviors. In particular, 3D-printed polymer scaffolds with diverse micro-/nanostructures offer a great potential for mimicking the structures of tissue. Consequently, they are foreseen as promissing pathways for regulating cell fates, including cell phenotype, differentiation of stem cells, as well as the migration and the proliferation of key cells, thereby facilitating tissue repairs and regenerations. Herein, the roles of structural functions of 3D-printed polymer scaffolds in regulating the fates and behaviors of numerous cells related to tissue repair and regeneration, along with their specific influences are highlighted. Additionally, the challenges and outlooks associated with 3D-printed polymer scaffolds with various structures for modulating cell fates are also discussed.

The Effect of Neutral Alpha-Glucosidase on Semen Parameters.

INTRODUCTION: The objective of this study was to investigate the relationship between the activity of neutral α-glucosidase in seminal plasma and semen quality and to explore the effect of secretory capability of the epididymis on male fertility. METHODS: A retrospective analysis of 542 men treated in the Center for Reproductive Medicine and Infertility from February to December 2022, the semen parameters and neutral α-glucosidase were tested and compared among different groups. These 542 men included normozoospermia, oligospermia, asthenospermia, and teratozoospermia. RESULTS: There was statistical difference in neutral alpha-glucosidase (NAG) level among different groups with different sperm concentration, motility, and morphology (p < 0.001). The NAG activity in seminal plasma was positively correlated with ejaculate volume and sperm concentration; meanwhile, a very weak positive correlation was found between NAG level and sperm motility, sperm morphology, respectively. CONCLUSIONS: Our results indicated that the secretion of NAG affected the volume, concentration, motility, and morphology of sperm to a certain extent. Given that NAG is a specific and marker enzyme in epididymis, where is the site of sperm maturation, we can conclude that there is a close relationship between NAG and sperm quality. Therefore, seminal plasma NAG has a definite clinical value in helping diagnosis of male infertility.

Photopolymerization Approach to Advanced Polymer Composites: Integration of Surface-Modified Nanofillers for Enhanced Properties.

The incorporation of functionalized nanofillers into polymers via photopolymerization approach has gained significant attention in recent years due to the unique properties of the resulting composite materials. Surface modification of nanofillers plays a crucial role in their compatibility and polymerization behavior within the polymer matrix during photopolymerization. This review focuses on the recent developments in surface modification of various nanofillers, enabling their integration into polymer systems through photopolymerization. The review discusses the key aspects of surface modification of nanofillers, including the selection of suitable surface modifiers, such as photoinitiators and polymerizable groups, as well as the optimization of modification conditions to achieve desired surface properties. The influence of surface modification on the interfacial interactions between nanofillers and the polymer matrix is also explored, as it directly impacts the final properties of the nanocomposites. Furthermore, the review highlights the applications of nanocomposites prepared by photopolymerization, such as sensors, gas separation membranes, purification systems, optical devices, and biomedical materials. By providing a comprehensive overview of the surface modification strategies and their impact on the photopolymerization process and the resulting nanocomposite properties, this review aims to inspire new research directions and innovative ideas in the development of high-performance polymer nanocomposites for diverse applications.

Hyaluronic acid hydrogels with excellent self-healing capacity and photo-enhanced mechanical properties for wound healing.

A continuously stable moist healing environment is immensely beneficial for wound healing, which can be availably achieved by providing an in situ hydrogel with enough strength resembling skin tissue and self-healing ability. Herein, through a dual-crosslinking strategy, hyaluronic acid-based hydrogels with excellent self-healing capacity and enhanced mechanical properties are fabricated via the acylhydrazone linkages and subsequent photocrosslinking based on hydrazide-modified sodium hyaluronate and aldehyde-modified maleic sodium hyaluronate. The hydrogels demonstrate the fast gelation process (< 1 min), the controlled swelling behaviors, and the good biocompatibility. Notably, they possess enhanced mechanical strength similar to the human dermis (∼ 2.2 kPa). Also, they can self-heal rapidly with a self-healing efficiency of ∼90 % at 6 h. Based on this, the hyaluronic acid-based hydrogels, without any biological factors involved, can facilitate the full-thickness skin wound reconstruction process by accelerating the three phases of the wound repair, including reducing wound inflammation in the inflammatory phase, promoting angiogenesis in the proliferative phase, and promoting the deposition and reconstruction of collagen in the remodeling phase. The produced hyaluronic acid hydrogel can serve as an ideal candidate for wound healing.

Spider Silk-Inspired Hyaluronic Acid-Based Hydrogels with Superior Self-Healing Capability and Enhanced Strength.

Hyaluronic acid hydrogels are promising materials for diverse applications, yet their potential is hampered by limitations such as low self-healing efficiency and insufficient mechanical strength. Inspired by the heterogeneous structures of spider silk, we introduce a novel dual dynamically crosslinked network hydrogel. This hydrogel comprises an acylhydrazone-crosslinked network, utilizing aldehyde hyaluronic acid (AHA) and 3,3'-dithiobis (propionohydrazide) (DTP) as a first network, and a secondary network formed by hydrogen bonds-crosslinked network between tannic acid (TA) and silk fibroin (SF) with ß-sheet formation. The hydrogel exhibits exceptional self-healing ability due to the dynamic and reversible nature of Schiff base bonds, disulfide bonds, and hydrogen bonds, achieving complete healing within 5 minutes. Additionally, the spider silk-inspired heterogeneous structures enhance mechanical properties. Furthermore, the incorporation of TA provides enhanced adhesion, as well as remarkable antibacterial and antioxidant properties. This innovative hyaluronic acid-based hydrogel, inspired by spider silk, offers a promising avenue to fortify both the mechanical strength and self-healing capabilities of hydrogels, thus expanding opportunities for applications in tissue engineering and biomedicine.

Cohort profile: the Johns Hopkins COVID Long Study (JHCLS)-a US nationwide prospective cohort study.

PURPOSE: COVID-19 continues to affect millions of individuals worldwide, both in the short and long term. The post-acute complications of SARS-CoV-2 infection, referred to as long COVID, result in diverse symptoms affecting multiple organ systems. Little is known regarding how the symptoms associated with long COVID progress and resolve over time. The Johns Hopkins COVID Long Study aims to prospectively examine the short-term and long-term consequences of COVID-19 in individuals both with and without a history of SARS-CoV-2 infection using self-reported data collected in an online survey. PARTICIPANTS: 16 764 adults with a history of SARS-CoV-2 infection and 799 adults without a history of SARS-CoV-2 infection who completed an online baseline survey. FINDINGS TO DATE: This cohort profile describes the baseline characteristics of the Johns Hopkins COVID Long Study. Among 16 764 participants with a history of SARS-CoV-2 infection and defined long COVID status, 75% reported a very good or excellent health status prior to infection, 99% reported experiencing at least one COVID-19 symptom during the acute phase of infection, 9.9% reported hospitalisation and 63% were defined as having long COVID using the WHO definition. FUTURE PLANS: Analysis of longitudinal data will be used to investigate the progression and resolution of long COVID symptoms over time.

Cohort profile: the Johns Hopkins COVID Long Study (JHCLS), a United States Nationwide Prospective Cohort Study.

Purpose: COVID-19 disease continues to affect millions of individuals worldwide, both in the short and long term. The post-acute complications of SARS-CoV-2 infection, referred to as long COVID, result in diverse symptoms affecting multiple organ systems. Little is known regarding how the symptoms associated with long COVID progress and resolve over time. The Johns Hopkins COVID Long Study aims to prospectively examine the short- and long-term consequences of COVID-19 disease in individuals both with and without a history of SARS-CoV-2 infection using self-reported data collected in an online survey. Participants: Sixteen thousand, seven hundred sixty-four adults with a history of SARS-CoV-2 infection and 799 adults without a history of SARS-CoV-2 infection who completed an online baseline survey. Findings to date: This cohort profile describes the baseline characteristics of the Johns Hopkins COVID Long Study. Among 16,764 participants with a history of SARS-CoV-2 infection and defined long COVID status, 75% reported a good or excellent health status prior to infection, 99% reported experiencing at least one COVID-19 symptom during the acute phase of infection, 9.9% reported a hospitalization, and 63% were defined as having long COVID using the WHO definition. Future plans: Analysis of longitudinal data will be used to investigate the progression and resolution of long COVID symptoms over time.

Efficacy of Yiqi Wenyang Huwei Decoction on airway inflammation in bronchial asthma in rats based on IL-25/NF-κB signaling pathway / 中成药

AIM To explore the mechanism of Yiqi Wenyang Huwei Decoction on airway inflammation improvement of rats with bronchial asthma based on IL-25/NF-κB signaling pathway.METHODS 60 rats were randomly divided into the control group,the model group,the dexamethasone group(0.2 mg/mL),the low-dose,medium-dose and high-dose Yiqi Wenyang Huwei Decoction groups(1,2,4 g/mL),with 10 rats in each group.Intraperitoneal injection of ovalbumin(OVA)and aluminum hydroxide suspension was applied to establish the rat asthma model,followed by 2-week corresponding dosing of the drugs.The rats of each group had their daily diet,mental status,hair growth and respiration observed;their differential count of inflammatory cells in bronchoalveolar lavage fluid(BALF)detected by automatic hematology analyzer;their pathological changes of lung tissue observed by HE staining;their pulmonary IL-25 protein expression detected by immunohistochemistry(IHC);their levels of IL-4,IL-5 and IL-13 in BALF measured by ELISA;their pulmonary expression of IL-25 and TRAF6 mRNA detected by RT-qPCR;and their pulmonary protein expressions of IL-25,TRAF6,IκBα,p-IκBα,NF-κB p65 and p-NF-κB p65 detected by Western blot.RESULTS Compared with the control group,the model group displayed severe damage of the lung tissue and infiltration of a large number of inflammatory cells;increased number of inflammatory cells and levels of IL-4,IL-5 and IL-13 in BALF(P<0.01);increased mRNA expressions of IL-25 and TRAF6,and pulmonary protein expressions of IL-25,TRAF6,p-IκBα/IκBα and p-NF-κB p65/NF-κB p65(P<0.01).Compared with the model group,all of the Yiqi Wenyang Huwei Decoction groups shared improved pulmonary infiltration of inflammatory cells;decreased number of inflammatory cells and levels of IL-4,IL-5 and IL-13 in BALF(P<0.05,P<0.01);and decreased mRNA expressions of IL-25 and TRAF6,and pulmonary protein expressions of IL-25,TRAF6,p-IκBα/IκBα and p-NF-κB p65/NF-κB p65(P<0.01).CONCLUSION Yiqi Wenyang Huwei Decoction can inhibit the airway inflammation in the rat model of bronchial asthma,which may be related to the inhibited activation of IL-25/NF-κB signaling pathway and the reduced expression of inflammatory factors.

Advances in synthesis of artemisinin based on plant genetic engineering / 中国中药杂志

Artemisinin is a kind of sesquiterpene lactone containing endoperoxide bridge,which is the most effective anti-malarial drug at present. However,low content of artemisinin in Artemisia annua,ranging from 0. 1%-1. 0% of dry weight,as well as the complicated extraction process have resulted in low yield and high cost of artemisinin,making it difficult to meet market demand.Based on the development of high-throughput sequencing and molecular biology,the related enzyme genes and transcription factors involved in the artemisinin metabolic pathway were cloned and identified. Metabolic engineering and synthetic biology methods to modify the original metabolic pathway of A. annua and genetic engineering in heterologous host cells have become one of the hotspots in this field. Therefore,the molecular mechanism of artemisin biosynthesis,different strategies of genetic modifications of A. annua,and the research status and application prospect of artemisinin synthesis in heterologous host cells( Nicotiana benthamiana,Physcomitrella patens) were summarized in our review,hoping to provide molecular basis and theoretical basis for breeding new varieties of A. annua with high artemisinin output.

Effects of mechanical ventilation and controlled spontaneous respiration on pulmonary function during short duration of general anesthesia with tracheal intubation / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effects of mechanical ventilation on pulmonary function during short duration of general anesthesia with tracheal intubation, and assess the safety of controlled spontaneous respiration during general anesthesia.</p><p><b>METHODS</b>Fifty-three adult patients (aged 18-55 years, ASA physical status I-II) scheduled for elective unilateral tympanoplasty were randomly assigned into mechanical ventilation group (group M, n=28) and spontaneous respiration group (group S, n=25). Anesthesia induction was performed in group M with intravenous propofol (2 mg/kg), fentanyl (3 microg<kg) and vecuronium (0.1 mg<kg), while with propofol (2 mg/kg), fentanyl (3 microg/kg) and sufficient superficial anesthesia on upper airway mucous membrane in group S. After tracheal intubation, mechanical ventilation began with VT 8 ml<kg and RR 10-12 bpm in group M, and spontaneous respiration was maintained in group S. Anesthesia was maintained by 0.7%-0.8% isoflurane and 60%-70% N(2)O at the end respiratory concentration to control MAC between 1.2-1.3. During the surgery, BIS values were controlled between 40-60, and propofol was administered when necessary. Vecuronium (1-2 mg) was given intermittently to maintain muscle relaxation and neostigmine (1 mg) with atropine 0.5 mg was administered intravenously before extubation in group M. No relaxant was used in group S. The parameters including heart rate (HR), mean blood pressure (MAP), pulse oxygen saturation (SpO(2)), and thoracic fluid content (TFC) were recorded before the induction and at 1, 5, 10, 20, 40, 60, 90, 120, and 150 min after intubation. Arterial blood was drawn immediately and 150 min after intubation for blood gases analysis and Alveolar-arterial oxygen gradient (P(A-a)DO(2)), and the respiratory index (RI) and dead volume/tidal volume (VD/VT) were calculated. The incidences of moving, bucking, swallowing, and status of awareness during surgery procedures were also recorded.</p><p><b>RESULTS</b>A total of 43 patients (group M, n=23; group S, n=20) were included in the study with 10 dropouts due to failed attempt to obtain arterial blood samples (8 patients) or severe bucking during intubation (2 patients). No significant differences were found in HR and MAP between the two groups (P>0.05). The pH and SpO(2) [ (97.9-/+1.00)% at the lowest] and PaO(2) in group S were significantly lower and the PaCO(2) was higher than those in group M (P<0.05). In group S, the pH values were 7.274-/+0.025 and 7.331-/+0.039, PaCO(2) values were 60-/+6 and 53-/+5 mmHg, and PETCO(2) values were 53-/+ 6 and 48-/+7 mmHg, and the PaO(2) values were 143-/+37 and 165-/+49 mmHg immediately and 150 min after the intubation, respectively. These values were considered safe under the concept of permissive hypercapnia. No significant differences were found in the P(A-a)DO(2), RI, VD/VT and TFC between or within the two groups (P>0.05), nor were moving, bucking, swallowing and awareness recorded during the surgical procedures.</p><p><b>CONCLUSION</b>In essentially normal lungs, short-term mechanical ventilation during general anesthesia with tracheal intubation does not damage the lung functions, and spontaneous respiration can offer sufficient oxygen supply without causing harmful carbon dioxide retention.</p>

Secreted expression of nonstructural protein gene 3ABC of foot-and-mouth disease virus in Sf9 cells and activity analysis / 生物工程学报

Entire 3ABC sequence of FMDV containing a 6 x his tag coding sequence at the N-terminal was obtained through PCR amplification using a pair of specific primers, subcloned into shuttle plasmid of pMelBac-B with a melittin secretion signal sequence and finally constructed recombinant plasmid of pMel-3ABC. After co-transfected the recombinant plasmid and linearized Bac-N-Blue DNA into Sf9 insect cell under intermediary agent of the Cellfectin, the result showed that we have already acquired recombinant baculovirus by screen of plaque assay and identification of PCR. Though the recombinant baculovirus infecting the Sf9 cells again, experiments indicated that 3ABC gene could express in insect cells and the expressed protein was secreted in the supernatant of Sf9 cell culture possessing favourable biological activities detected by adopting two methods of SDS-PAGE and Western blot. The result verified that the protein could respond with sera derived from FMDV infected animals, but have no responsibility with sera derived from health animals and vaccinated animals detected by indirect ELISA using antigen of expressed protein after purification with Ni-NTA his bind resin. Therefore, this study has established a solid foundation for establishing an effective diagnosis method to discriminating the FMDV infected animals from vaccinated animals.

Correlation of changes in circulating bone marrow stem cells in pregnant rabbits after acute myocardial infarction with serum estradiol / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes in circulating bone marrow stem cells in pregnant rabbits after AMI (AMI) and their relationship with estradiol.</p><p><b>METHODS</b>Three groups of rabbits were used, namely pregnancy and AMI group, AMI group without pregnancy, and sham operation group with pregnancy. The ratio of CD90(+) cells in the peripheral blood was determined with flow cytometry in all the rabbits, and serum estradiol level measured. Four weeks after AMI, hemodynamic measurements were carried out. The morphological changes of the myocardial tissues were examined with ImageJ 1.31.</p><p><b>RESULTS AND CONCLUSION</b>Four weeks after AMI, the two pregnancy groups showed a higher Left ventricular end systolic pressure(LVESP) and+dp/dtmax, lower left ventricular end-diastolic pressure (LVEDP) and -dp/dtmax and high levels of CD90(+) cells in peripheral blood than AMI group without pregnancy (P<0.01). The ratio of circulating CD90(+) cells increased gradually with gestational age and peaked at the end stage of pregnancy. After delivery the circulating CD90+ cell ratio decreased sharply, showing a significant correlation with serum estradiol level (r=0.725, P<0.01). Four weeks after AMI, the pregnancy group had smaller myocardial infarction (MI) volume than the non-pregnant group (22.17+/-6.34% vs 38.86+/-5.97%, P<0.05). Circulating bone marrow stem cells increased during pregnancy with gestational age and peaked at the end stage of pregnancy. Ten days after delivery, the stem cells resumed basically the normal level. The proportion of circulating bone marrow stem cells was significantly correlated with the level of serum estradiol during pregnancy, and mobilization of the bone marrow stem cells induced by acute ischemic event in pregnant rabbits was advanced. 4 weeks after AMI, the pregnant rabbits showed better heart contraction and diastolic function than the non-pregnant ones.</p>

Migration of intravenously grafted mesenchymal stem cells to injured heart in rats / 生理学报

The present study aimed to determine the role of tissue injury in migration of mesenchymal stem cells (MSCs) intravenously transplanted into heart and to establish experimental basis for improving stem cell therapy in its targeting and effectiveness. MSCs were isolated from bone marrow of male Sprague-Dawley rats and purified by density centrifuge and adhered to the culture plate in vitro. Female rats were divided randomly into four groups. Myocardial ischemia (MI) transplanted group received MSCs infusion through tail vein 3 h after MI and compared with sham-operated group or normal group with MSCs infusion, or control group received culture medium infusion. MI was created in female rats by ligating the left anterior descending coronary artery. The heart was harvested 1 week and 8 weeks after transplantation. The characteristics of migration of MSCs to heart were detected with expression of sry gene of Y chromosome by using fluorescence in situ hybridization (FISH). Ultrastructural changes of the ischemic myocardium of the recipient rats were observed by transmission electron microscope (TEM). One week or 8 weeks after transplantation, sry positive cells were observed in the cardiac tissue in both of MI transplanted group and sham-operated group, the number of sry positive cells being significantly higher in MI transplanted group (P<0.01). No significant difference was found in the number of sry positive cells between 1 week and 8 weeks after transplantation. No sry positive cells were observed in the hearts of control and normal group. In addition, the ultrastructure of some cells located in the peri-infarct area of MI rats with MSCs transplantation was similar to that of MSCs cultured in vitro. These results indicate that MSCs are capable of migrating towards ischemic myocardium in vivo and the fastigium of migration might appear around 1 week after MI. The tissue injury and its degree play an important role in the migration of MSCs.