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An efficient protocol for the synthesis of furans through Rh(III)-catalyzed vinyl C-H activation from acrylic acids and α-diazocarbonyl compounds has been developed. The reaction features broad functional group tolerance and affords a series of furans in moderate to good yields. Moreover, no additives such as copper or silver salts are required. Some control experiments are performed to give insight into the mechanism of this cascade transformation and the decarbonylation process is involved in the formation of the furan product.

The efficient synthesis of pyranones is presented by a three-component cascade reaction from readily available acrylic acids, ethyl glyoxylate, and

A coupling of acrylic acids/benzoic acids with α-diazocarbonyl compounds has been realized by a combined catalytic system of rhodium catalyst and Zn(OAc)

Investigating the fatigue performance of high-strength bolt is essential to prevent related accidents. An axial-tensile fatigue test under a stress ratio of 0.5 was performed on 21 specimens of high-strength bolts to investigate the constant-amplitude fatigue performance of grade 8.8 M24 high-strength bolts. Based on experimental results, S–N curves were obtained through regression analysis, and fractographic analysis was conducted on typical specimens. Moreover, the results were compared with the existing fatigue experimental results and standards. Further, a finite element model was established to analyze the stress distribution of the bolts. It was found that the fatigue strength of the high-strength bolt at 2 × 106 cycles under a stress ratio of 0.5 was 89.76 MPa, which is 1.60 to 1.87 times greater than the values specified in the current standards. Through the comparison of the fatigue tests under stress ratios of 0.3, 0.5, and 0.8, the fatigue strength decreased as the stress ratio increased. Additionally, two main fatigue failure modes were found, with most bolts fracturing at the root of the first loaded thread; this is confirmed by the stress concentration location obtained from finite element analysis. The fracture morphology of the bolts exhibited a single-point fatigue source and possessed obvious fatigue fracture characteristics. It was concluded that the area of the fatigue propagation region was basically inversely proportional to stress ratio.

A carboxyl-assisted C-H functionalization of acrylic acids with formaldehyde to give butenolides is described. It is the first time that the addition of an inert vinylic C-H bond to formaldehyde has been achieved via cobalt-catalyzed C-H activation. The unique reactivity of the cobalt species was observed when compared with related Rh or Ir catalysts. γ-Hydroxymethylated butenolides were produced by the treatment of Na2CO3 after the catalytic reaction in one pot.

An efficient rhodium-catalyzed protocol for the synthesis of cyclopentenones based on a three-component reaction of acrylic acids, formaldehyde, and malonates via vinylic C-H activation is reported. Exploratory studies showed that 5-alkylation of as-prepared cyclopentenones could be realized smoothly by the treatment of a variety of alkyl halides with a Na2CO3/MeOH solution. Excess formaldehyde and malonate led to a multicomponent reaction that afforded the multisubstituted cyclopentenones through a Michael addition.

Ochratoxin A (OTA) is a toxic metabolite produced mainly by Aspergillus and Penicillium species. A quantitative method was developed for the rapid, simple, and sensitive detection of OTA in corn by quantum dots–based fluorescent immunochromatographic assay (QDs-ICA). The CdSe/ZnS QDs–labelled anti-OTA monoclonal antibody (mAb) conjugates were designed as the fluorescent signal probe. The QDs-ICA included the designation of test line (T line) and control line (C line), which were sprayed with optimal concentrations of the OTA-OVA and staphylococcal protein-A (SPA), respectively. Under the optimal experimental conditions, the QDs-ICA exhibited excellent specificity and good accuracy and precision. For qualitative detection, the cut-off value for the T line of the visual detection method was 2.5 ng/mL. For quantitative detection, the linear regression equation of the standard curve was y = 0.366x + 0.514 with a reliable correlation coefficient (R2 = 0.992). Moreover, the 50% inhibition value (IC50) of the QDs-ICA was 0.91 ng/mL, the limit of detection (LOD) was 0.07 ng/mL, and the detection range was 0.05 to 10 ng/mL. In addition, the recovery rates ranged from 91.82 to 100.35% with a coefficient of variation (CV) below 3% for intra-assay, whereas the recovery rates for inter-assay changed from 94.29 to 104.62% with a CV below 10%. These results indicate that the QDs-ICA can serve as a potential large-scale preliminary device for rapid determination of OTA.

A three-component reaction from readily available low-cost materials of benzoic acids, formaldehyde, and malonates for the preparation of indanones by rhodium catalysis is reported. The annulation ...

Diaryl ethers are synthesized directly from simple arenes for the first time through dual C(sp2)–H activation with the aid of a bidentate auxiliary by nickel catalysis. The anion of the additive is crucial to the transformation, and the control experiments reveal that the acyloxylated benzamide is the key intermediate.

Catalytic wet air oxidation (CWAO) is a harmless, cheap and effective technology for the degradation of toxic containments directly to CO

BACKGROUND Haplo-identical hematopoietic stem cell transplantation (HSCT) has provided potential donors for patients lacking available HLA-matched donors. ABO blood type compatibility has been reported to be associated with HSCT outcomes. However, few studies have investigated the role of ABO compatibility in haplo-identical HSCT of AML patients. MATERIAL AND METHODS We retrospectively analyzed 42 adult acute myeloid leukemia (AML) patients who received unmanipulated haplo-identical peripheral blood HSCT at the Chinese PLA General Hospital between Jan 2013 and Dec 2017. We analyzed the role of ABO compatibility in engraftment, transfusion requirements, cytomegalovirus (CMV) and Epstein-Barr virus (EBV) viremia, acute graft-versus-host disease (GVHD), overall survival (OS), transplantation-related mortality (TRM), relapse, chronic GVHD, and post-transplant lymphoproliferative disorder (PTLD). RESULTS There were no significant differences between the ABO-matched group and the ABO-mismatched group in terms of engraftment, transfusion requirements, CMV and EBV viremia, OS, TRM, relapse, PTLD, and chronic GVHD. Univariate analysis revealed ABO incompatibility is not an independent risk factor of engraftment, transfusion requirements, CMV and EBV viremia, OS, TRM, relapse, PTLD, and chronic GVHD. We found a significantly higher cumulative incidence of aGVHD in the matched group compared with the mismatched group (80.95% vs. 42.86%, p=0.020). In multivariate analysis, ABO mismatch was associated with decreased risk of acute GVHD within 100 days after transplant (hazard ratio 0.492, 95% confidence interval 0.2123-1.14). However, the difference was not statistically significant (p=0.099). CONCLUSIONS This study demonstrated ABO incompatibility is not an independent risk factor of outcomes for AML patients who received unmanipulated haplo-identical peripheral blood HSCT. ABO compatibility might have limited value in haplo-identical donor selection.

Background: Multi-kinase inhibitor sorafenib showed dramatic effects in acute myeloid leukemia (AML) cells harboring fms-related tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutation. However, FLT3-ITD mutation only occurs in 25% of AML cases. The therapeutic effects of sorafenib in AML patients without FLT3-ITD are still in need of further investigation. Methods: A young AML patient with central nervous system (CNS) relapse was treated with sorafenib combined with chemotherapy. Another patient with refractory AML arising form chronic myelomonocytic leukemia (CMML) was treated with sorafenib monotherapy. Spinal and cranial magnetic resonance imaging (MRI), minimal residual disease (MRD) and peripheral blood cell count were monitored to evaluate disease status. Results: The patient with CNS relapse exhibited significant shrink of tumor volume. The other patient with refractory AML achieved hematological improvements. Conclusion: These two cases suggested that sorafenib might be utilized as a potent salvage therapy for some refractory/relapsed AML patients without the FLT3-ITD mutation.

Fleroxacin (FLE) is a broad-spectrum fluoroquinolone antibiotic widely used in animal husbandry, veterinary medicine and aquaculture. Eating animal-derived foods with FLE residues can cause allergies, poisoning or drug resistance. The water-soluble QDs (CdSe/ZnS) and anti-FLE monoclonal antibody (mAb) were used to prepare a fluorescent probe by the method of N-(3-dimethylaminopropyl)-N′-ethylcarbodimide hydrochloride (EDC) activation. The fluorescent probe was characterized by dynamic light scattering (DLS). The better bioactivity and stability of the fluorescent probe was obtained under the pH value of 8.0, the molecule molar ratio of EDC (1 : 2000) and anti-FLE monoclonal antibodies (1 : 10). The control line (C line) and test line (T line) of a nitrocellulose (NC) filter membrane were sprayed with SPA (0.05 mg mL−1) and FLE-OVA (1.4 mg mL−1) solutions with optimal concentration, respectively. A novel method of fluorescent immunochromatographic assay based on quantum dots (QDs-ICA) in this work exhibited good accuracy, reproductivity and excellent specificity under the optimal experimental conditions. Compared with the traditional method for the visual detection of FLE, the developed QDs-ICA can successfully determine FLE residues in pork meat with a better cut-off value of 2.5 ng mL−1. The QDs-ICA could be adapted for the rapid preliminary detection of FLE residues in pork meat for the first time.

Zearalenone (ZEN), a type of non-steroidal estrogenic mycotoxin, is mainly produced by several species of Fusarium molds. It is ubiquitous in contaminated grains and grain products all over the world, posing a serious threat to animal and human health. This study aims to screen the mimotopes of ZEN from a phage display random 12-mer peptide library and explore their immunogenicity. A monoclonal antibody (mAb) against ZEN was employed as the target for mimotope selection from a phage display random peptide library. After four rounds of panning, six mimotopes that could specifically bind to ZEN mAb were obtained. In order to explore the immunogenicity of these mimotopes, Balb/c mice were immunized with phages Z8, Z21, Z35, Z8:Z21:Z35(1:1:1) and the conjugate of ZEN-bovine serum albumin (ZEN-BSA), respectively. The titers of antibodies in the mice immunized with mimotopes were 1:3200 (Z8), 1:3200 (Z21), 1:6400 (Z35), 1:6400 (1:1:1 mixture of Z8, Z21 and Z35), and the binding between serum antibodies and ZEN-OVA could be blocked by ZEN standards. These results demonstrated that the mimotopes of ZEN could induce specific antibodies against ZEN, suggesting that these displayed peptides were immunogenic.

A sensitive and accurate multiple fluorescence immunoassay for the simultaneous quantitative detection of Zearalenone (ZEN) and Ochratoxin A (OTA) in single spot based on multicolor quantum dots (QDs) labeling was developed for the first time. Two kinds of ZnCdSe/ZnS (core/shell) QDs with maximum emission wavelengths at 520 nm (green) and 610 nm (orange-red) were selected as marking materials, respectively. The anti-ZEN-mAb-QDs and anti-OTA-mAb-QDs were designed as the immune fluorescent probes. Fluorescence was measured at the same excitation wavelength and two different emission wavelengths to determine each target. The procedure for QDs-based multiple fluorescence labeled immunosorbent assay (M-FLISA) was developed. The 50% inhibition concentrations (IC50) of ZEN and OTA were 0.034 and 1.175 ng/mL. Moreover, the limits of detection (LOD) for the simultaneous determination were 0.0239 and 2.339 ng/g for ZEN and OTA in maize, respectively. In addition, the recoveries ranged from 93.15 to 101.90% for ZEN and from 95.29 to 102.43% for OTA, with the coefficient variation (CV) of 2.70–8.86% and 3.51–6.22% respectively. There was good consistency between the M-FLISA and high performance liquid chromatography (HPLC) results, which confirmed that the M-FLISA was suitable for the simultaneous quantitative detection of various mycotoxins.

An efficient rhodium(III)-catalyzed C–H activation followed by intermolecular annulation between enamides and sulfoxonium ylides has been developed. The transformation proceeds smoothly with a broad range of substrates, affording a series of isoquinoline derivatives in moderate to good yields under additive-free conditions.

A three-component reaction from readily available low-cost materials of benzoic acids, formaldehyde, and malonates for the preparation of indanones by rhodium catalysis is reported. The annulation is initiated by an

BACKGROUND: Oral mucositis (OM) affects the quality of life and therapeutic outcomes of cancer patients. More effective drugs and methods for treating OM are urgently required for clinical application. Extracellular vesicles can play important roles in cutaneous wound healing. However, their role in OM remains unclear. Our aim was to investigate the function and mechanisms of topical coatings of extracellular vesicles derived from human umbilical cord mesenchymal stem cells (hUC-MSC-EVs) in OM. METHODS: HUC-MSC-EVs were isolated by differential ultracentrifugation. We used glacial acetic acid to induce the formation of OM in rats. HUC-MSC-EVs were covered on the OM topically once a day. Rats’ body weights were measured on alternative days. The healing degree of OM was evaluated with macroscopic observations and histological examinations. We also analyzed the mechanisms of hUC-MSC-EVs when promoting the healing of OM. The expression levels of NF-κB, IL-6, TNF-α, and IL-1β in mucosal tissue were evaluated using immunohistochemistry. RESULTS: The median healing time of OM in the blank control, rhaFGF, 0.25 µg/µL EVs, 0.75 µg/µL EVs, and 1.50 µg/µL EVs groups was 14, 11, 10, 7, and 11 days, respectively. The most significant effect of hUC-MSC-EVs in promoting healing was at the concentration of 0.75 µg/µL. The median healing scores in the 0.75 µg/µL EVs group were 4 on day 5 and 3 on day 8 (*P

Catalytic wet air oxidation (CWAO) is a harmless, cheap and effective technology for the degradation of toxic containments directly to CO2 and H2O. In this work, highly dispersed Cu(II)/Cu(I)-N that embedded in the framework of g-C3N4 (Cux-g-C3N4) were synthesized in a facile thermal polymerization method and used in the CWAO of phenols, antibiotics and vitamins. Characterization results confirmed that g-C3N4 formed in the prepared catalyst and copper was chemically coordinated with N in g-C3N4, which inhibited the aggregation of copper. Meanwhile, Cu(II) or Cu(I) in the framework of g-C3N4 was more effective for the degradation of phenol than Cu(0) and CuO, and more than 23 toxic containments could be degraded under mild conditions. The prominent performance of Cu0.1-g-C3N4 for CWAO reaction was discussed on the base of these experiments and it was disclosed that in-situ formed H2O2 might be contributed to the highly activity.

Ochratoxin A (OTA) is a toxic metabolite produced mainly by Aspergillus and Penicillium species. A quantitative method was developed for the rapid, simple, and sensitive detection of OTA in corn by quantum dots-based fluorescent immunochromatographic assay (QDs-ICA). The CdSe/ZnS QDs-labelled anti-OTA monoclonal antibody (mAb) conjugates were designed as the fluorescent signal probe. The QDs-ICA included the designation of test line (T line) and control line (C line), which were sprayed with optimal concentrations of the OTA-OVA and staphylococcal protein-A (SPA), respectively. Under the optimal experimental conditions, the QDs-ICA exhibited excellent specificity and good accuracy and precision. For qualitative detection, the cut-off value for the T line of the visual detection method was 2.5 ng/mL. For quantitative detection, the linear regression equation of the standard curve was y = 0.366x + 0.514 with a reliable correlation coefficient (R

An efficient protocol for the cobalt-catalyzed acyloxylation of arenes and alkenes with the assistance of an 8-aminoquinolyl auxiliary group is reported. In this transformation, benzoic acids, alkenyl acids, and aliphatic acids could be readily involved to afford structurally diverse esters. It is worth noting that the silver sulfate (Ag2SO4) oxidant is renewable and the directing group could be removed and recycled. The strategy represents the first successful example of transition metal-catalyzed acyloxylation of alkenyl carboxamides C(sp(2))-H bonds with carboxylic acids.

A novel extractant, 5-octyloxymethyl-7-bromo-8-quinolinol (HBrO8Q), was employed to extract Pd(II) from low-acidity aqueous solution. The extraction behaviors indicated that HBrO8Q had high extraction efficiency and selectivity for Pd(II) under the experimental conditions, and the stoichiometry of Pd(II) with HBrO8Q was found to be 1:1 by means of mole ratio method and Job’s method. The thermodynamic study indicated that the extraction process was endothermic and spontaneous. Additionally, complete back extraction of palladium could be achieved by using acidic thiourea solution.

A new and straightforward protocol for the synthesis of quinoline N-oxides from the annulation of arylnitrones and alkynes is described. For the first time, a [4+2] cyclization of nitrone and alkynes has been achieved by cobalt catalysis via a nitrone-assisted dual C-H cleavage under relatively mild conditions.

A nickel-catalyzed stereoselective alkenylation of an unactivated β-C(sp3)–H bond in aliphatic amide with terminal alkynes using 8-aminoquinoline auxiliary is reported for the first time. This reaction displays excellent functional group tolerance with respect to both aliphatic amides and terminal alkynes and features a cheap nickel catalytic system. The 8-aminoquinolyl directing group could be smoothly removed, and the resultant β-styrylcarboxylic acid derivatives could serve as versatile building blocks for further transformation.

Herein, a one-pot approach to the synthesis of 2,4-dialkenylindoles by rhodium-catalyzed dual C–H alkenylation and decarboxylation of indole-3-carboxylic acids with alkenes is described. This protocol provided facile access to diverse 2,4-dialkenylindoles, which were found to exhibit intense fluorescence in the range of 472–530 nm with a quantum yield of up to 0.57 in CH2Cl2.

Cp*Co(III)-catalyzed direct allylation of enamides has been accomplished with the exclusive formation of allylated Z-enamides with high efficiency. In addition, the employment of maleimides as the reaction partner under the same catalytic conditions provides a series of succinimide-substituted Z-enamides.

A novel method for the synthesis of multisubstituted oxazoles by palladium-catalyzed oxidative cyclization of N-acyl enamides has been developed. The reaction employs readily available iodobenzenes and enamides as the starting materials under mild reaction conditions and provides a reliable way to achieve versatile substituted oxazole derivatives.

A rhodium-catalyzed redox-neutral reaction of arylhydrazines with sulfoxonium ylides to construct 2-arylindole derivatives in one pot has been developed. The transformation proceeds efficiently under mild conditions and involves tandem C–H activation and an intramolecular dehydration annulation sequence, providing a straightforward pathway to access pharmaceutically and biologically valuable 1-aminoindole derivatives.

BACKGROUND Post-transplant lymphoproliferative disorder (PTLD) is a rare complication following solid organ transplantation and allogeneic hematopoietic stem cell transplantation (Allo-HSCT), which gives rise to high mortality rates. MATERIAL AND METHODS This was a single-center retrospective analysis based on 27 patients who were diagnosed with PTLD following Allo-HSCT between January 1, 2007 and June 2018 at the Chinese PLA General Hospital. The purpose of this analysis was to investigate responses and prognostic factors of rituximab-based treatment. RESULTS Twenty-seven patients were treated with rituximab. Among them, 20 of 27 patients (74.07%) had a complete response, 2 of 27 patients (7.41%) had a partial response, 5 of 27 patients (18.52%) had no response, and 22 of 27 patients (81.48%) cleared Epstein-Barr virus (EBV) copies. There were no obvious side effects. The 1-year overall survival (OS) estimate was 46.8% (95% CI, 23.1-65.5%). Univariate analysis revealed that lower OS was correlated with Eastern Cooperative Oncology Group (ECOG) score standard (3-4), Epstein-Barr virus (EBV) viral load (≥10⁶ copies/mL), bacteria or fungal infection, and EBV reactivation were positive after treatment with 1 or 2 doses of rituximab (P

Cobalt-catalyzed C-H amination of arenes with alkylamines by the assistance of 8-aminoquinoline as auxiliary through sp(2) C-H bond functionalization has been achieved. Attractive features of this protocol include the low loading of the cobalt catalyst and the readily available reagents.

A nickel-catalyzed facile synthesis of structurally diverse five-membered lactams from aliphatic amides and terminal acetylenes with the assistance of an 8-aminoquinolyl auxiliary has been achieved. A broad range of terminal acetylenes and aliphatic amides proved to be the efficient coupling partners, furnishing the corresponding lactams in moderate to good yields. The transformation is proven to undergo an oxidative alkynylation followed by the intramolecular annulation process. The methodology can be extended to aromatic amides and acrylamides, which provides an efficient and straightforward protocol for the construction of a variety of isoindolinone and pyrrolidinone derivatives.

A new method of cobalt-catalyzed annulation of anilides and internal alkynes for the efficient synthesis of quinoline scaffolds was developed. The combination of cobalt catalyst with the Lewis acid Zn(OTf)2 ensured the success of the annulation to give the quinoline heterocycles in high efficiency. The transformation is supposed to undergo ortho C–H activation and nucleophilic addition of C–Co species toward the amides. Attractive features of this system include the use of a low cost cobalt catalyst, the easy-handling operation, and readily available substrates.

An efficient and regioselective cobalt-catalyzed synthesis of multi-substituted pyrroles is reported by the use of readily available enamides and alkynes. The success of the process relies on the employment of a catalytic amount of Cp*Co(CO)I2 together with CuO as the oxidant.

A highly efficient protocol for the synthesis of pyrrolidones by the copper-catalyzed alkynylation/annulation of aliphatic amides with alkynyl carboxylic acids is discussed in this paper. A broad range of easily accessible alkynyl carboxylic acids were introduced at the b-methyl group of aliphatic amides with the assistance of an 8-aminoquinolyl auxiliary group via decarboxylation to achieve the subsequent cyclic C-N bond formation within one hour. High selectivity of b-methyl groups over methylene groups was observed, and the extension of this catalytic system to the activation of methylene C-H bonds failed. The substrates with two different groups at the a-position of the aliphatic amides lead to the formation of diastereoisomers which is determined by (HNMR)-H-1 spectroscopy. The initially produced products with Z-configurations can be easily transformed to the corresponding products with Econfigurations by the treatment with dilute p-toluenesulfonic acid after the reaction. This catalytic tandem decarboxylative cyclization provides a new opportunity for the direct functionalization of sp(3)C-H bonds.

A mild and efficient protocol for the synthesis of 2,2′-difunctional biaryls from readily available benzamides and oximes by Co(OAc)2·4H2O catalysis has been developed. The catalytic cycle that includes aerobic oxidation of Co(I) to Co(III) is successfully achieved for the first time through dual-chelation-assisted C–H/C–H coupling with the assistance of catalytic Mn(acac)3. The catalytic system exhibits powerful reactivity and tolerates a large number of sensitive functional groups.

The ruthenium(II)-catalyzed direct ring-opening reaction of 7-azabenzonorbornadienes with anilides via C-H activation to access hydronaphthylamines has been developed. The transformation proceeds with a high stereoselectivity to give cis-configuration products under redox-neutral conditions.