Visible-Light-Induced Synthesis of 3-Alkyl Chromones under Catalyst- and Additive-Free Conditions.

Herein, we reported an efficient and facile visible-light-induced 3-alkyl chromone synthesis from easily accessible o-hydroxyaryl enaminones and α-diazo esters. In this protocol, excellent yields were obtained with a broad substrate scope at room temperature, tolerating various functional groups. Of note is that this eco-friendly methodology features catalyst- and additive-free, mild reaction conditions, simple operation procedure, and easy scale-up, which affords a convenient pathway for the preparation of 3-alkyl chromones. Experimental results and density functional theory (DFT) computation analyses confirm the participation of carbene species and active cyclopropane intermediate.

Photocatalytic Benzylic C-H Oxidation/Cyclization of Enaminones to the Synthesis of Polysubstituted Oxazoles.

Photocatalytic benzylic C-H oxidation/cyclization of enaminones was efficiently achieved to afford oxazole derivatives under mild conditions. The oxygen in the oxazole ring originated from green oxidant molecular oxygen. The synthetic protocol features broad substrate scopes and good functional group tolerance. The combined experimental and theoretical studies reveal that in suit benzylic C-H oxidation/cyclization is involved in the reaction transformations.

Alterations of Bax/Bcl-2 ratio contribute to NaAsO2 induced thyrotoxicity in human thyroid follicular epithelial cells and SD rats.

The environmental toxicant arsenic causes various human diseases and threatens millions of people worldwide. Recently, a limited number of studies have revealed that exposure to arsenic is associated with thyroid dysfunction, indicating its toxicological impact on the thyroid gland, however, its precise forms of damage and underlying mechanisms remain largely unknown. Here, we sought to observe the thyrotoxicity of sodium arsenite (NaAsO2) on human thyroid follicular epithelial cells (Nthy-ori 3-1) and SD rats, and explore the role of Bax/Bcl-2 ratio in the above process. Our results displayed that NaAsO2 exerted a dose-dependent inhibitory effect on the viability of Nthy-ori 3-1 cells. Alongside the increase doses of NaAsO2 exposure, morphological changes and elevated LDH levels were observed. Furthermore, apoptosis rates increased in a dose- and time-dependent manner, accompanied by a decrease in Bcl-2 and an opposite change in Bax expression. SD rats were treated with 0, 2.5, 5, and 10 mg/kg NaAsO2 for 36 weeks. Our findings revealed that NaAsO2 exposure resulted in arsenic accumulation in thyroid tissue, elevated ratio of Bax/Bcl-2, and histopathological changes of thyroid in rats, which accompanied by the decreased serum T3 and T4 levels and the increased serum TSH level. Furthermore, T3 and T4 levels were negatively correlated with Bax expression, whereas positively correlated with Bcl-2 expression. Collectively, our results suggest that NaAsO2 exposure induces cytotoxicity in Nthy-ori 3-1 cells, causes structural damages and dysfunction of thyroid in SD rats, in which the imbalance of Bax/Bcl-2 ratio may play a significant role.

Electrochemical S-H and O-H insertion reactions from thiols or salicylic acids with diazo esters.

An electrochemical carbenoid insertion reaction of diazo compounds into C-S and C-O bonds with electricity as the oxidant has been reported in this work. In this protocol, this transformation proceeded smoothly under mild conditions at room temperature in the absence of a catalyst and a ligand. In addition, the yield of the S-H insertion product was up to 96% and the O-H product could be efficiently obtained in up to 80% yield. Of note is that this environmentally friendly strategy exhibited excellent applicability in gram-scale synthesis.

Machine learning aided inverse design for few-mode fiber weak-coupling optimization.

Few-mode fiber (FMF) supporting many modes with weak-coupling is highly desired in mode division multiplexing (MDM) systems. The multi-parameter design of FMF becomes comparably difficult, inaccurate and time-consuming when it comes for complex fiber structures and many high order modes. In this work, we demonstrate a machine learning method using neural network to inversely design the desired FMF based on multiple-ring structure. By using the minimum index difference between adjacent modes as the weak-coupling optimization aim, we realize the inverse design of 4-ring step-index FMFs for supporting 4, 6 and 10 -mode operation, and 6-ring step-index FMF for supporting 20-mode operation. This method provides high-accuracy, high-efficiency and low-complexity for fast and reusable design of optical fibers, including particularly weak-coupling FMF in this work. It can be widely extended to a lot of fibers and has great potential for instantaneous applications in the optical fiber industry.

Design, synthesis, and biological evaluation of dihydroartemisinin-fluoroquinolone conjugates as a novel type of potential antitubercular agents.

Tuberculosis remains a global public health problem in recent years. To develop novel type of potential antitubercular agents, twelve novel dihydroartemisinin-fluoroquinolone (DHA-FQ) conjugates (three types of molecules) were gradually designed and conveniently synthesized. All the newly synthesized conjugates were well characterized and evaluated against different Mycobacterium tuberculosis strains in vitro. The screening results showed that five DHA-FQ conjugates were active toward M. tuberculosis H37Rv, and compound 3a exhibited the strongest inhibitory activity (MIC=0.0625 µg/mL), which was comparable to the positive control Moxifloxacin and even stronger than Ofloxacin. Conjugates 2a and 3a also displayed comparable activities against various clinically isolated sensitive and resistant M. tuberculosis strains (MIC=0.125-16 µg/mL) to Moxifloxacin. All target compounds possessed selective anti-M. tuberculosis ability. Preliminary structure-activity relationship demonstrated that short linker between DHA and FQ was favorable for strong antitubercular activity. This study provides a new clue for the development of novel antitubercular lead molecules.

Recent insights into greywater treatment: a comprehensive review on characteristics, treatment technologies, and pollutant removal mechanisms.

With the rapid socio-economic and industrial development, the problem of water shortage is becoming increasingly serious. Seeking alternative water sources to reduce the need for freshwater resources is an increasing concern. Household greywater production is high and accounts for about 50-80% of domestic wastewater. In recent years, the in situ treatment and reuse of greywater have received widespread attention. Treated greywater can be used for non-potable purposes such as toilet flushing and irrigation, which can greatly reduce the pressure of freshwater resource shortage. This paper reviews the sources and characteristics of greywater and analyzes its quantity and quality. In addition, this paper outlines and summarizes various greywater treatment technologies commonly used, including physical, biological, and chemical treatment technologies, as well as combination technologies. Understanding the mechanisms of contaminant removal is essential for effective greywater treatment. While discussing different treatment technologies, we focus on the removal mechanisms of pollutants from greywater, including organics, nutrients, surfactants, and emerging contaminants. Finally, future perspectives on greywater management and reuse are presented. Through a comprehensive review, we expect that this review will help the reader to better understand the characteristics of greywater and to more rationally select the appropriate treatment technology based on the removal mechanism of pollutants.

Case Report: Complete Remission of C1q Nephropathy Treated With a Single Low-Dose Rituximab, a Reality or Coincidence?

C1q nephropathy is a glomerulopathy that is characterized by large amount of C1q deposits in the glomerular mesangium. It is a diagnosis of exclusion after ruling out systemic lupus erythematosus and membranoproliferative glomerulonephritis by systemic and serological examination. The pathogenesis of C1q nephropathy is unclear. In addition, there is very little generalizability in the treatment and prognosis for pediatric C1q nephropathy due to diversities in clinical manifestations and pathological types. Rituximab is a human/mouse chimeric monoclonal antibody against CD20, which is primarily used for treating lymphomas and, most recently, has been used to treat certain kidney diseases including C1q nephropathy. In this report, we used one quarter of the typical dose of rituximab for lymphoma treatment to achieve complete remission in a C1q nephropathy patient, significantly reducing deposition of immune complexes and glomerular damage. This case indicates that dosage reconsiderations may be necessary for rituximab in treatment of pediatric C1q nephropathy.