Straightforward Access to Free ß2,3,3-Amino Acids through One Pot C-H Activation/C-C Cleavage.

The first synthesis of unnatural ß2,3,3-amino acids with a spirocyclic backbone by one-pot protocol has been presented. This reaction features wide functional group tolerance and feasibility of post-functionalization of natural products and biologically important molecules. Novel dipeptide and tripeptide structures were assembled using this newly developed ß2,3,3-amino acid in high efficiency. The combination of C-H activation and C-C cleavage for the synthesis of ß-amino acids would trigger more promising synthetic routes for this compound.

Possible sarcopenia and risk of new-onset type 2 diabetes mellitus in older adults in China: a 7-year longitudinal cohort study.

BACKGROUND: Previous studies have shown that type 2 diabetes mellitus (T2DM) can cause sarcopenia; however, these conditions may have a bidirectional association. This study aimed to explore the longitudinal association between possible sarcopenia and new-onset T2DM. METHODS: We conducted a population-based cohort study using nationally representative data from the China Health and Retirement Longitudinal Study (CHARLS). This study included participants aged ≥ 60 years who were free of diabetes during the baseline survey of CHARLS (2011 to 2012) and were followed up until 2018. Possible sarcopenia status was defined according to the Asian Working Group for Sarcopenia 2019 criteria. Cox proportional hazards regression models were used to evaluate the effect of possible sarcopenia on new-onset T2DM. RESULTS: In total, 3,707 individuals were enrolled in this study, with a median age of 66 years; the prevalence of possible sarcopenia was 45.1%. During the 7-year follow-up, 575 cases (15.5%) of incident diabetes were identified. Participants with possible sarcopenia were more likely to have new-onset T2DM than those without possible sarcopenia (hazard ratio: 1.27, 95% confidence interval: 1.07-1.50; p = 0.006). In subgroup analysis, we found a significant association between possible sarcopenia and T2DM in individuals aged < 75 years or with a BMI < 24 kg/m². However, this association was not significant in individuals aged ≥ 75 years or with a BMI ≥ 24 kg/m². CONCLUSIONS: Possible sarcopenia is associated with an increased risk of new-onset T2DM in older adults, especially in individuals who are not overweight and aged 75 years or younger.

Merging Imidazolidines with a Trifluoromethylated Tetrasubstituted Carbon through Tungsten Catalyzed 1,3-Dipolar Cycloaddition.

An unprecedented 1,3-dipole cycloaddition between acyclic CF3-ketimines and N-benzyl azomethine ylide has been allowed by tungsten catalysis, furnishing a range of novel imidazolidines bearing a trifluoromethylated tetrasubstituted carbon center. This reaction appears as one of rare examples that challenging acyclic CF3-ketimines have been engaged in 1,3-cycloaddition reactions. The capability for gram-scale synthesis and variant derivatizations of cycloaddition adducts illustrates the synthetic potential of this approach. This protocol provides a facile access to a rapidly enlarging pool of motifs with a trifluoromethylated fully substituted carbon.

Delivering 2-Aryl Benzoxazoles through Metal-Free and Redox-Neutral De-CF3 Process.

An unexpected cleavage of the Csp3-CF3 bond of CF3-hydrobenzoxazoles has been disclosed, affording a range of 2-aryl benzoxazoles under metal-free and redox-neutral conditions. This transformation has demonstrated broad substrate scope and good compatibility of functional groups. 2-Aryl benzothiazole and 2-aryl benzoimidazole could be smoothly assembled in the same manner. On the basis of preliminary mechanistic studies, base initiated and aromatization driven ß-carbon elimination was considered to be the key step for the formation of 2. This reaction offers an alternative, facile, and sustainable route to access important 2-aryl benzoxazole motifs.

Mucilaginibacter xinganensis sp. nov., a phenanthrene-degrading bacterium isolated from wetland soil.

An aerobic, Gram-stain negative, rod-shaped and non-motile strain, BJC16-A31T, was isolated from the wetland soil sample taken from Daxing'anling, Heilongjiang, People's Republic of China. Strain BJC16-A31T was found to be oxidase- and catalase-positive, and produced light orange colonies on modified R2A agar. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BJC16-A31T is closely related to Mucilaginibacter gotjawali SA3-7T with 96.54% sequence similarity and it formed a separate lineage in the genus Mucilaginibacter. Strain BJC16-A31T contained menaquinone-7 (MK-7) as the predominant isoprenoid quinine. Anteiso-C15:0, C16:0 and anteiso-C15:0 were the major fatty acids. The major polar lipids were phosphatidylethanolamine, six unidentified polar lipid, two unidentified aminophospholipids and one unidentified aminolipid. The genome is composed of a circular 5,301,339 bp chromosome with average G + C percentage of 42.25%. The Average Nucleotide Identity (ANI) between strain BJC16-A31T and M. gotjawali SA3-7T was 77.51%. Combined phenotypic, chemotaxonomic, phylogenetic and genomic characteristics support the conclusion that strain BJC16-A31T represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter xinganensis sp. nov. is proposed. The type strain is BJC16-A31T (= CGMCC 1.12728T = NBRC 110384T).

Association of Adrenergic Receptor α2A (α2A-AR) Gene rs1800544 Polymorphism with Bone Mineral Density and Bone Turnover Markers in an Elderly Chinese Population.

BACKGROUND Adrenergic receptor α2A (α2A-AR) is up-regulated in osteoporotic bone osteoblasts. Previous research demonstrated an association between polymorphism of a2A-AR gene and bone mineral density (BMD) as well as bone turnover markers (BTMs) in the Slovenian population. The present study aimed to investigate the association of rs1800544 polymorphism of α2A-AR gene with BMD and BTMs in the Chinese elderly population with osteoporosis (OP) or with osteoporotic fractures. MATERIAL AND METHODS A total of 346 unrelated elderly individuals were recruited in the study. Rs1800544 polymorphism was determined by Snapshot technology. BTMs were determined by electrochemiluminescence. BMDs at lumbar spine (LS) and proximal femur were measured with dual-energy X-ray absorptiometry (DEXA). Hardy-Weinberg equilibrium and distribution of genotype frequencies were verified using the chi-squared test. Analysis of co-variance (ANCOVA) adjusted for confounding factors was performed to explore the relationship of rs1800544 polymorphism with BMD and BTMs in all participants and in subgroups. RESULTS The genotype distributions in all subjects and in subgroups conformed to Hardy-Weinberg equilibrium (P>0.1). Distribution of genotype frequencies of subgroups showed no significant differences (P>0.05). Patients with GG genotype in the fracture group had significantly higher serum BTMs level compared with those carrying other genotypes (P<0.05). No significant association between rs1800544 and BTMs was detected in the elderly population with OP. Comparison of BMD at each site in all participants did not show any significant difference in subgroups with CC, CG, and GG genotypes (P>0.05). CONCLUSIONS Rs1800544 polymorphism is associated with BTMs level in Chinese elderly individuals with osteoporotic fractures, indicating the involvement of genetic variation of a2A-AR gene in bone metabolism.

A systematic review of complications in thoracic spine surgery for ossification of ligamentum flavum.

STUDY DESIGN: Systematic review. OBJECTIVES: The aim of this systematic review is to summarize the incidence of complications, to relate complication incidence to procedures performed, to assess the impact of the year of study publication and follow-up duration on complication incidence. METHODS: The authors conducted the Cochrane Central Register of Controlled Trials, PubMed, and EMBASE searches for relevant literatures. The incidence of complications was summarized. Correlation of the incidence with year of study publications, follow-up duration, and the surgical outcome was statistically evaluated. RESULTS: A total of 16 studies met our inclusion criteria, including 475 patients. All of these studies were retrospective case series. The mean age of patients ranged from 55 to 64 years. Average follow-up duration ranged from 26 to 65 months. Partial patients in four studies underwent surgeries and reserved posterior structure of the spinal canal. The others underwent operations removing posterior structure of spinal canal. The mean recovery rate from each individual study varied between 31 and 68% and the pooled neurologic function recovery rate was 53% (95% CI: 43-62%). The mean complication rate was 24%. Cerebrospinal fluid leakage was the most reported postoperative complication (19%), then neurologic deterioration (5%). Other complications included local infections, wound dehiscence, increased kyphotic deformity, an hematoma. CONCLUSIONS: Operations removing posterior structure of spinal canal are the main technique to decompress spinal cord. Cerebrospinal fluid leakage and postoperative neurologic deterioration were the most reported complications.

Copper-catalyzed site-selective intramolecular amidation of unactivated C(sp³)-H bonds.

The intramolecular dehydrogenative amidation of aliphatic amides, directed by a bidentate ligand, was developed using a copper-catalyzed sp(3) C-H bond functionalization process. The reaction favors predominantly the C-H bonds of ß-methyl groups over the unactivated methylene C-H bonds. Moreover, a preference for activating sp(3) C-H bonds of ß-methyl groups, via a five-membered ring intermediate, over the aromatic sp(2) C-H bonds was also observed in the cyclometalation step. Additionally, sp(3) C-H bonds of unactivated secondary sp(3) C-H bonds could be functionalized by favoring the ring carbon atoms over the linear carbon atoms.

Possible sarcopenia and risk of hip fracture in older adults in China.

BACKGROUND: The Asian Working Group for Sarcopenia (AWGS) introduced the concept of "possible sarcopenia" in 2019. However, the association between possible sarcopenia and hip fracture is not well characterized. Hence, we conducted a study to explore this association in older Chinese adults. METHODS: This was a population-based cohort study based on nationally representative data from the China Health and Retirement Longitudinal Study. Individuals aged ≥60 years with no history of hip fracture at baseline (2011-2012) were included and followed up until September 2018. Possible sarcopenia was defined based on the AWGS 2019 criteria during the study period, and the occurrence of hip fractures was monitored. The association between possible sarcopenia and hip fractures was assessed using Cox proportional hazards regression models. RESULTS: A total of 4,011 participants were included, of whom 44.8 % had possible sarcopenia. During the 7-year follow-up, 197 individuals experienced hip fractures. Individuals with possible sarcopenia had a significantly higher risk of hip fractures than those without possible sarcopenia (hazard ratio: 2.00, 95 % confidence interval: 1.46-2.75; P < 0.001). The association was consistently observed across various subgroups based on age, sex, and overweight status. CONCLUSIONS: This study identified possible sarcopenia as a significant risk factor for hip fractures in older Chinese adults. These findings underscore the importance of addressing possible sarcopenia as a preventive measure to reduce the incidence of hip fractures.

Synthesis of Indolyl Phenyl Diketones through Visible-Light-Promoted Ni-Catalyzed Intramolecular Cyclization/Oxidation Sequence of Ynones.

The combination of visible light catalysis and Ni catalysis has enabled the synthesis of indolyl phenyl diketones through the cyclization/oxidation process of ynones. This reaction proceeded under mild and base-free conditions and showed a broad scope and feasibility for gram-scale synthesis. Several natural products and biologically interesting molecules could be readily postfunctionalized by this method.

A quinoline derivative-based supramolecular gel for fluorescence 'turn-off' detection of Fe3+and Cu2.

In this research, we synthesized and constructed a novel gelator (namedQN) combining quinoline and naphthalene that self-assembled in N, N-dimethylformamide (DMF) to form a stable supramolecular gel (namedOQN). Under UV light, gelOQNexhibited extremely bright yellow fluorescence. The gelOQNshowed excellent sensing performance for both Fe3+and Cu2+, with a fluorescence 'turn-off' detection mechanism and the lowest detection limit of 7.58 × 10-8M and 1.51 × 10-8M, respectively. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectra, x-ray powder diffraction (XRD), rheological measurements, x-ray photoelectron spectroscopy (XPS), and fluorescence spectroscopy were used to characterize the gelOQN. TheOQNion-responsive membrane created is an excellent fluorescent writing material.

Copper-catalyzed aerobic intramolecular dehydrogenative cyclization of N,N-disubstituted hydrazones through C(sp(3)-H functionalization.

An aerobic activity: The title reaction proceeds through an oxidation/cyclization/aromatization sequence under an atmosphere of O(2) (see scheme; DBU=1,8-diazabicyclo[5.4.0]undec-7-ene, DCE=1,2-dichloroethane, DMS=dimethylsulfide). This coupling reaction is the first to proceed via an iminium intermediate for a C(sp(3)-H bond-functionalization process, and provides an environmentally friendly and atom-efficient access to substituted pyrazoles.

Synthesis of Aryl-methylene Ethers through Pd(0)-Catalyzed Coupling between Hydrobenzoxazoles and Dichloromethane.

Using dichloromethane (DCM) as the C1 feedstock, the first Pd(0)-catalyzed synthesis of aryl-methylene ether motifs from hydrobenzoxazoles (hydrothiazoles) has been reported. This protocol has exhibited an ample substrate scope (38 examples) and wide functional group tolerance. Aryl-methylene ether adducts have been successfully engaged in coupling with isocyanate to provide bis-iminoisoindolinones. In this reaction, DCM has served as a twofold electrophile for reaction with hydrobenzoxazoles via double C-Cl bond cleavage.

Efficacy and safety of flurbiprofen cataplasms versus loxoprofen sodium cataplasms in knee osteoarthritis: a randomized controlled trial.

BACKGROUND: Clinical trial evidence is limited to identify better topical non-steroidal anti-inflammatory drugs (NSAIDs) for treating knee osteoarthritis (OA). We aimed to compare the clinical efficacy and safety of flurbiprofen cataplasms (FPC) with loxoprofen sodium cataplasms (LSC) in treating patients with knee OA. METHODS: This is an open-label, non-inferiority randomized controlled trial conducted at Peking University Shougang Hospital. Overall, 250 patients with knee OA admitted from October 2021 to April 2022 were randomly assigned to FPC and LSC treatment groups in a 1:1 ratio. Both medications were administered to patients for 28 days. The primary outcome was the change of pain measured by visual analog scale (VAS) score from baseline to day 28 (range, 0-10 points; higher score indicates worse pain; non-inferiority margin: 1 point; superiority margin: 0 point). There were four secondary outcomes, including the extent of pain relief, the change trends of VAS scores, joint function scores measured by the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and adverse events. RESULTS: Among 250 randomized patients (One patient without complete baseline record in the flurbiprofen cataplasms was excluded; age, 62.8 ± 10.5 years; 61.4% [153/249] women), 234 (93.6%) finally completed the trial. In the intention-to-treat analysis, the decline of the VAS score for the 24-h most intense pain in the FPC group was non-inferior, and also superior to that in the LSC group (differences and 95% confidence interval, 0.414 (0.147-0.681); P <0.001 for non-inferiority; P = 0.001 for superiority). Similar results were observed of the VAS scores for the current pain and pain during exercise. WOMAC scores were also lower in the FPC group at week 4 (12.50 [8.00-22.50] vs . 16.00 [11.00-27.00], P = 0.010), mainly driven by the dimension of daily activity difficulty. In addition, the FPC group experienced a significantly lower incidence of adverse events (5.6% [7/124] vs . 33.6% [42/125], P <0.001), including irritation, rash and pain of the skin, and sticky hair uncovering pain. CONCLUSIONS: This study suggested that FPC is superior to LSC for treating patients with knee OA in pain relief, joint function improvement, and safety profile.

Brønsted acid-catalyzed efficient Strecker reaction of ketones, amines and trimethylsilyl cyanide.

A general method for the one-pot, three-component Strecker reaction of ketones was developed using Brønsted acids as organocatalysts. A series of alpha-aminonitriles were obtained in good to excellent yields (79-99%). A preliminary extension to a catalytic enantioselective three-component Strecker reaction of ketones (up to 40% ee) is also described.

The [3+2] Annulation of CF3-Ketimines by Re Catalysis: Access to CF3-Containing Amino Heterocycles and Polyamides.

Transition metal catalyzed [3 + 2] annulation of imines with double bonds via directed C-H activation offers a direct access to amino cyclic motifs. However, owing to weak coordination and steric hindrance, trifluoromethylated ketimines have been an unaddressed challenge for TM-catalyzed annulations. Here, a rhenium-catalyzed [3 + 2] annulation of trifluoromethylated ketimines with isocyanates via C(sp2)-H activation has been disclosed. This approach provides an efficient platform for rapid access to a privileged library of CF3-containing iminoisoindolinones and polyamides by utilizing challenging CF3-ketimines as the annulation component. The capability of gram scale synthesis, the post-functionalization of the cyclization adduct, the derivation of complex natural molecules and the facile synthesis of polyamides highlight a diversity of synthetic potential of the current methodology.

Synthesis of ß-CF3 ß-Amino Esters with an Indane Backbone by Rhenium-Catalyzed [3+2] Annulation.

The [3+2] annulation of trifluoromethylated ketimines with acrylates has been enabled by rhenium-catalyzed C-H activation, delivering a variety of ß-CF3 ß-amino esters. The reaction has exhibited broad substrate generality regarding aromatic CF3-ketimines and acrylates, the ability for gram scale synthesis, and facile derivation of the annulation products. The transformation is one of the few examples in which challenging sp2 C-H bonds of CF3-ketimines have been functionalized. The rapid assembly of biologically important fluorinated ß-amino esters by this strategy will benefit the related studies and inspire a new approach for fluorinated motif synthesis.

Associations of LRP5 Gene With Bone Mineral Density, Bone Turnover Markers, and Fractures in the Elderly With Osteoporosis.

Objective: The study aimed to explore the associations of rs4988300 and rs634008 in the low-density lipoprotein receptor-related protein 5 (LRP5) gene with bone mineral density (BMD), bone turnover markers (BTM), and fractures in elderly patients with osteoporosis (OP). Methods: Our study included 328 unrelated OP patients with or without fractures. Genomic DNA was extracted for genotyping. BTM levels were assessed by electrochemiluminescence (ECL). Dual-energy X-ray absorptiometry (DXA) was employed to measure BMD in the lumbar spine (LS) and proximal femur. Basic features between the OP and fracture groups were analyzed using the t-test. The Chi-square test was performed to analyze the differences in allele and genotype frequencies. The associations of single-nucleotide polymorphisms (SNPs) with BMD and BTM in the subgroups were investigated by the analysis of covariance (ANCOVA) adjusted for confounding factors. Results: In both females and males, individuals with fractures exhibited higher BTM levels and lower BMD values than those with OP (P < 0.05). The allele and genotype frequencies of rs4988300 in the subgroups were significantly different (P < 0.05). In both females and males suffering from OP, participants with rs4988300 GG or rs634008 TT presented lower procollagen I N-terminal propeptide (PINP) levels (P < 0.05). Women with OP carrying rs4988300 GG exhibited lower BMD values at FN and TH (P < 0.05). In both females and males with fractures, individuals carrying rs4988300 GG genotype or rs634008 TT genotype exhibited lower PINP levels and BMD values at FN and TH than those with other genotypes (P < 0.05). Conclusions: Rs4988300 and rs634008 polymorphisms in the LRP5 gene are associated with bone phenotypes in the elderly with OP or fractures.

A perfect double role of CF3 groups in activating substrates and stabilizing adducts: the chiral Brønsted acid-catalyzed direct arylation of trifluoromethyl ketones.

A direct and efficient Brønsted acid-promoted arylation of tri- and difluoromethyl ketones, as well perfluoroalkyl ketones, has been developed; good to excellent enantioselectivities (up to 99% ee) were achieved.

Associations of IDUA and PTCH1 with Bone Mineral Density, Bone Turnover Markers, and Fractures in Chinese Elderly Patients with Osteoporosis.

INTRODUCTION: Osteoporosis (OP) is a common polygenic disorder in the aging population, and several single nucleotide polymorphisms (SNPs) in the alpha-L-iduronidase (IDUA) gene and patched homolog 1 (PTCH1) gene regulate bone metabolism and affect bone mass. The study aimed at investigating the relationships of rs3755955 and rs6831280 in the IDUA gene and rs28377268 in the PTCH1 gene with bone mineral density (BMD), bone turnover markers (BTMs), and fractures in the elderly Chinese subjects with OP. MATERIALS AND METHODS: A cohort of 328 unrelated senile osteoporosis (SOP) patients with or without osteoporotic fractures was recruited. rs3755955, rs6831280, and rs28377268 polymorphisms were identified using SNaPshot technology. BTM levels were determined by electrochemiluminescence (ECL). Bone mineral densities (BMDs) at the lumbar spine (LS) and proximal femur sites were measured by dual-energy X-ray absorptiometry (DEXA) in all subjects. The Hardy-Weinberg equilibrium (HWE) test was performed. HWE P values and comparisons of genotype frequencies were estimated using the chi-square test. Analysis of covariance (ANCOVA) adjusted for confounding factors was performed to investigate associations of SNPs with BMDs and BTMs in subgroups. RESULTS: The chi-square test indicated that genotype distributions in the control group conformed to HWE (P > 0.05). The distributions of allele and genotype frequencies of rs6831280 between fracture and osteoporotic participants were significantly different (P-allele = 0.002 and P-genotype = 0.012, respectively). Concerning rs6831280, ANCOVA found BMDs at LS 2-4 (L2-4) and total hip (TH) among the study subjects suffering from SOP with GA genotype were lower than in those carrying GG or AA (P-L2-4 = 0.004 and P-TH = 0.027, respectively). CONCLUSIONS: IDUA rs6831280 is associated with BMDs at L2-4 and TH in the elderly Chinese population with SOP and may serve as a marker for the genetic susceptibility to osteoporotic fractures.