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1.
J Synchrotron Radiat ; 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38843004

RESUMEN

Laser-induced projectile impact testing (LIPIT) based on synchrotron imaging is proposed and validated. This emerging high-velocity, high-strain microscale dynamic loading technique offers a unique perspective on the strain and energy dissipation behavior of materials subjected to high-speed microscale single-particle impacts. When combined with synchrotron radiation imaging techniques, LIPIT allows for in situ observation of particle infiltration. Two validation experiments were carried out, demonstrating the potential of LIPIT in the roentgenoscopy of the dynamic properties of various materials. With a spatial resolution of 10 µm and a temporal resolution of 33.4 µs, the system was successfully realized at the Beijing Synchrotron Radiation Facility 3W1 beamline. This innovative approach opens up new avenues for studying the dynamic properties of materials in situ.

2.
Mol Phylogenet Evol ; 191: 107993, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38103706

RESUMEN

Brisingida Fisher 1928 is one of the seven currently recognised starfish orders, and one of the least known taxa as being exclusive deep-sea inhabitants. Modern deep-sea expeditions revealed their common occurrences in various deep-sea settings including seamounts, basins and hydrothermal vent peripheral, underlining the necessity of clarifying their global diversity and phylogeny. In this study, we present a comprehensive molecular phylogeny of Brisingida which encompasses the highest taxonomic diversity to date. DNA sequences (COI, 16S, 12S and 28S) were obtained from 225 specimens collected in the global ocean, identified as 58 species spanning 15 of the 17 extant genera. Phylogenetic relationship was inferred using both maximum likelihood and Bayesian inference methods, revealing polyphyletic families and genera and indicating nonnegligible bias in prior morphology-based systematics. Based on the new phylogeny, a novel classification of the order, consisting of 5 families and 17 genera, is proposed. Families Odinellidae, Brisingasteridae and Novodiniidae (sensu Clark and Mah, 2001) were resurrected to encompass the genera Odinella, Brisingaster and Novodinia. Brisingidae and Freyellidae were revised to include 11 and 3 genera, respectively. A new genus and species, two new subgenera and seven new combinations are described and a key to each genus and family is provided. Transformations of morphological traits were evaluated under the present phylogenetic hypothesis. A series of paedomorphic characters were found in many genera and species, which led to a high degree of homoplasy across phylogenetically distant groups. Our results provide new insights in the phylogeny and ontogeny of the order, and highlight the necessity to evaluate character convergence under sound phylogenetic hypothesis.


Asunto(s)
Equinodermos , Estrellas de Mar , Humanos , Animales , Equinodermos/genética , Estrellas de Mar/genética , Filogenia , Teorema de Bayes , Secuencia de Bases
3.
Chemistry ; : e202401540, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38805347

RESUMEN

Imines are essential intermediates in organic transformations, and is generally produced by dehydrogenative condensation of alcohols and amines with the assist of specialized catalysts and additives. Heterogeneous photocatalysis provides a sustainable platform for such process without the using of toxic oxidants, yet a functionalized photocatalyst with optimized co-adsorption of reactants needs to be developed to promote the stoichiometric oxidative condensation under ambient conditions. Here, we show that benzyl alcohol and aniline adsorb non-interferingly on the Fe node and the linker sites of the MIL-53(Fe) metal organic frameworks (MOFs), respectively. The co-adsorption of both reactants barely influences the reduction of molecular oxygen to generate oxygen radicals, resulting in efficient formation of benzaldehyde under visible light. Additionally, the weak adsorption of water together with surface acidity of the MIL-53(Fe) promote a rapid condensation of benzaldehyde with aniline and the depletion of generated water, achieving an efficient C-N bond creation for a wide range of substrates.

4.
Eur Radiol ; 34(3): 1481-1492, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37796294

RESUMEN

OBJECTIVES: Sonochemotherapy, which uses microbubble (MB)-assisted ultrasound (US) to deliver chemotherapeutic agents, has the potential to enhance tumour chemotherapy. The combination of US and MB has been demonstrated to prolong the survival of patients with pancreatic cancer. This phase 2 clinical trial aimed to determine the clinical efficacy and safety of sonochemotherapy for inoperable pancreatic ductal adenocarcinoma by using US and MB. METHODS: Eighty-two patients with stage III or IV pancreatic cancer were recruited from July 2018 to March 2021 and followed up until September 2022. US treatment was performed with a modified diagnostic US scanner for 30 min after chemotherapeutic infusion. The primary endpoint was overall survival (OS), and the secondary endpoints were Eastern Cooperative Oncology Group (ECOG) status < 2, progression-free survival (PFS), disease control rate (DCR), and adverse events. RESULTS: Seventy-eight patients were randomly allocated (40 to chemotherapy and 38 to sonochemotherapy). The median OS was longer with sonochemotherapy than with chemotherapy (9.10 vs. 6.10 months; p = 0.037). The median PFS with sonochemotherapy was 5.50 months, compared with 3.50 months (p = 0.080) for chemotherapy. The time of ECOG status < 2 was longer with sonochemotherapy (7.20 months) than with chemotherapy (5.00 months; p = 0.029). The DCR was 73.68% for sonochemotherapy compared with 42.50% for the control (p = 0.005). The incidence of overall adverse events was balanced between the two groups. CONCLUSIONS: The use of sonochemotherapy can extend the survival and well-being time of stage III or IV pancreatic cancer patients without any increase in serious adverse events. TRIAL REGISTRATION: ChineseClinicalTrials.gov ChiCTR2100044721 CLINICAL RELEVANCE STATEMENT: This multicentre, randomised, controlled trial has proven that sonochemotherapy, namely, the combination of diagnostic ultrasound, microbubbles, and chemotherapy, could extend the overall survival of patients with end-stage pancreatic ductal adenocarcinoma from 6.10 to 9.10 months without increasing any serious adverse events. KEY POINTS: • This is the first multicentre, randomised, controlled trial of sonochemotherapy for clinical pancreatic cancer treatment using ultrasound and a commercial ultrasound contrast agent. • Sonochemotherapy extended the median overall survival from 6.10 (chemotherapy alone) to 9.10 months. • The disease control rate increased from 42.50% with chemotherapy to 73.68% with sonochemotherapy.


Asunto(s)
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Microburbujas , Neoplasias Pancreáticas/terapia , Neoplasias Pancreáticas/tratamiento farmacológico , Resultado del Tratamiento , Carcinoma Ductal Pancreático/diagnóstico por imagen , Carcinoma Ductal Pancreático/terapia , Ultrasonografía , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico
5.
Arterioscler Thromb Vasc Biol ; 43(5): 654-673, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36994729

RESUMEN

BACKGROUND: Infantile hemangioma (IH) arises as a result of dysregulation of both angiogenesis and vasculogenesis. The deubiquitylase OTUB1 (OTU domain, ubiquitin aldehyde binding 1) has been reported to play an essential role in multiple cancers; however, its function in the progression of IH and the underlying mechanisms regulating angiogenesis remain unclear. METHODS: Transwell assays, EdU assays, and tube formation assays were performed to investigate the biological behavior of IH in vitro. IH animal models were established to estimate the progression of IH in vivo. Mass spectrometric analysis were conducted to detect the downstream of OTUB1 and ubiquitination sites of transforming growth factor beta induced (TGFBI). Half-life assays and ubiquitination test were performed to investigate the interaction between TGFBI and OTUB1. Extracellular acidification rate assays were employed to estimate the glycolysis level in IH. RESULTS: The expression of OTUB1 was obviously increased in proliferating IH as compared to the involuting and involuted IH tissues. Through in vitro experiments, the knockdown of OTUB1 inhibited the proliferation, migration and tube formation of human hemangioma endothelial cells, while the overexpression of OTUB1 promoted the proliferation, migration and angiogenic abilities of human hemangioma endothelial cells. The knockdown of OTUB1 significantly suppressed IH progression in vivo. Furthermore, TGFBI was predicted as a functional downstream target of OTUB1 in IH by mass spectrometry. Mechanistically, OTUB1 interacted with and deubiquitylated TGFBI on the K22 and K25 residues, which was demonstrated to be independent of the catalytic activity of OTUB1. The inhibitory effects of OTUB1 knockdown on cell proliferation, migration and tube formation ability of human hemangioma endothelial cells were reversed by TGFBI overexpression. Further, we found that OTUB1 mediated glycolysis by regulating TGFBI in infantile hemangioma. CONCLUSIONS: OTUB1 deubiquitinates TGFBI in a catalytic-independent manner and promotes angiogenesis in infantile hemangioma by regulating glycolysis. Targeting OTUB1 might be an effective therapeutic strategy for inhibiting IH progression and tumor angiogenesis.


Asunto(s)
Células Endoteliales , Hemangioma , Animales , Humanos , Proliferación Celular , Células Endoteliales/metabolismo , Glucólisis , Hemangioma/tratamiento farmacológico , Factor de Crecimiento Transformador beta/metabolismo , Biocatálisis
6.
J Nanobiotechnology ; 22(1): 61, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38355548

RESUMEN

Despite recent advancements in cancer treatment, this disease still poses a serious threat to public health. Vaccines play an important role in preventing illness by preparing the body's adaptive and innate immune responses to combat diseases. As our understanding of malignancies and their connection to the immune system improves, there has been a growing interest in priming the immune system to fight malignancies more effectively and comprehensively. One promising approach involves utilizing nanoparticle systems for antigen delivery, which has been shown to potentiate immune responses as vaccines and/or adjuvants. In this review, we comprehensively summarized the immunological mechanisms of cancer vaccines while focusing specifically on the recent applications of various types of nanoparticles in the field of cancer immunotherapy. By exploring these recent breakthroughs, we hope to identify significant challenges and obstacles in making nanoparticle-based vaccines and adjuvants feasible for clinical application. This review serves to assess recent breakthroughs in nanoparticle-based cancer vaccinations and shed light on their prospects and potential barriers. By doing so, we aim to inspire future immunotherapies for cancer that harness the potential of nanotechnology to deliver more effective and targeted treatments.


Asunto(s)
Vacunas contra el Cáncer , Nanopartículas , Neoplasias , Humanos , Nanovacunas , Inmunoterapia , Vacunas contra el Cáncer/uso terapéutico , Neoplasias/tratamiento farmacológico , Adyuvantes Inmunológicos , Nanopartículas/uso terapéutico
7.
J Nanobiotechnology ; 22(1): 7, 2024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-38166931

RESUMEN

Radionuclides internal radiotherapy (RIT) is a clinically powerful method for cancer treatment, but still poses unsatisfactory therapeutic outcomes due to the hypoxic characteristic of tumor microenvironment (TME). Catalase (CAT) or CAT-like nanomaterials can be used to enzymatically decompose TME endogenous H2O2 to boost TME oxygenation and thus alleviate the hypoxic level within tumors, but their effectiveness is still hindered by the short-lasting of hypoxia relief owing to their poor stability or degradability, thereby failing to match the long therapeutic duration of RIT. Herein, we proposed an innovative strategy of using facet-dependent CAT-like Pd-based two-dimensional (2D) nanoplatforms to continuously enhance RIT. Specifically, rationally designed 2D Pd@Au nanosheets (NSs) enable consistent enzymatic conversion of endogenous H2O2 into O2 to overcome hypoxia-induced RIT resistance. Furthermore, partially coated Au layer afford NIR-II responsiveness and moderate photothermal treatment that augmenting their enzymatic functionality. This approach with dual-effect paves the way for reshaping TME and consequently facilitating the brachytherapy ablation of cancer. Our work offers a significant advancement in the integration of catalytic nanomedicine and nuclear medicine, with the overarching goal of amplifying the clinical benefits of RIT-treated patients.


Asunto(s)
Nanopartículas , Neoplasias , Humanos , Peróxido de Hidrógeno , Microambiente Tumoral , Hipoxia/tratamiento farmacológico , Catálisis , Nanomedicina , Línea Celular Tumoral , Neoplasias/tratamiento farmacológico , Neoplasias/radioterapia
8.
Molecules ; 29(8)2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38675507

RESUMEN

Astaxanthin was encapsulated in liposomes by a thin layer dispersion and ultrasound method using soybean phospholipid. The digestion properties of liposomes for encapsulating astaxanthin were investigated in light of particle size, size distribution, zeta potential, and microstructure during in vitro digestion as a function of time. These results exhibited that the average particle size increased gradually with liposomal vesicles retained round shapes and a fairly uniform distribution after passage through the simulated gastric fluid digestion. The result revealed that astaxanthin-loaded liposomes were stable in low pH conditions. It was also found that the mixed micelles formed in a simulated intestinal fluid. The zeta potential of astaxanthin-loaded liposomes had a decrease in negativity after digestion. In comparison with free astaxanthin, there was an appreciable increase in the bioaccessibility of astaxanthin after encapsulation in liposomes. This enhancement can be attributed to more soluble astaxanthin in the mixed micelles for astaxanthin-loaded liposomes. It indicated that the barrier of the liposomal bilayer could inhibit astaxanthin fading and leaking after encapsulation in liposomes. These results provide useful information for designing more stable delivery systems in the gastrointestinal tract and improving the bioaccessibility of lipophilic nutraceuticals.


Asunto(s)
Liposomas , Tamaño de la Partícula , Xantófilas , Xantófilas/química , Xantófilas/farmacocinética , Liposomas/química , Disponibilidad Biológica , Concentración de Iones de Hidrógeno , Micelas , Composición de Medicamentos , Digestión , Fosfolípidos/química
9.
Angew Chem Int Ed Engl ; 63(12): e202318783, 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38258371

RESUMEN

We herein present an approach of photo-induced disproportionation for preparation of Type-I photodynamic agents. As a proof of concept, BODIPY-based photosensitizers were rationally designed and prepared. The photo-induced intermolecular electron transfer between homotypic chromophores leads to the disproportionation reaction, resulting in the formation of charged intermediates, cationic and anionic radicals. The cationic radicals efficiently oxidize the cellularimportant coenzyme, tetrahydrobiopterin (BH4 ), and the anionic radicals transfer electrons to oxygen to produce superoxide radicals (O2 - ⋅). One of our Type-I photodynamic agents not only self-assembles in water but also effectively targets the endoplasmic reticulum. It displayed excellent photocytotoxicity even in highly hypoxic environments (2 % O2 ), with a half-maximal inhibitory concentration (IC50 ) of 0.96 µM, and demonstrated outstanding antitumor efficacy in murine models bearing HeLa tumors.


Asunto(s)
Biopterinas/análogos & derivados , Fotoquimioterapia , Superóxidos , Ratones , Animales , Fármacos Fotosensibilizantes/farmacología , Especies Reactivas de Oxígeno , Oxígeno
10.
J Am Chem Soc ; 145(9): 5353-5362, 2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36853085

RESUMEN

Photocatalysis provides an eco-friendly route for the hydrogenation of aromatic carbonyls to O-free aromatics, which is an important refining process in the chemical industry that is generally carried out under high pressure of hydrogen at elevated temperatures. However, aromatic carbonyls are often only partially hydrogenated to alcohols, which readily desorbs and are hardly further deoxygenated under ambient conditions. Here, we show that by constructing an oxide surface over the Pd cocatalyst supported on graphitic carbon nitride, an alternative hydrogenation path of aromatic carbonyls becomes available via a step-wise acetalization and hydrogenation, thus allowing efficient and selective production of O-free aromatics. The PdO surface allows for optimum adsorption of reactants and intermediates and rapid abstraction of hydrogen from the alcohol donor, favoring fast acetalization of the carbonyls and their consecutive hydrogenation to O-free hydrocarbons. The photocatalytic hydrogenation of benzaldehyde into toluene shows a high selectivity of >90% and a quantum efficiency of ∼10.2% under 410 nm irradiation. By adding trace amounts of HCl to the reaction solution, the PdO surface remains stable and active for long-term operation at high concentrations, offering perspective for practical applications.

11.
Cancer Sci ; 114(3): 806-821, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36369903

RESUMEN

Infantile hemangioma (IH) is the most common benign tumor in infancy. Propranolol, a nonselective ß-adrenergic receptor blocker, is now the first-line therapy for IH. Recently, low sensitivity to propranolol therapy has become one major reason for the failure of IH treatment. However, the exact underlying mechanisms are yet to be fully elucidated. Here, we reported that pyruvate kinase isoform M2 (PKM2), an essential glycolytic enzyme, played a critical role in regulating the progression of IH and the therapeutic resistance of propranolol treatment. Shikonin reversed the propranolol resistance in hemangioma-derived endothelial cells and in hemangioma animal models. Moreover, shikonin combined with propranolol could induce excessive reactive oxygen species (ROS) accumulation and lead to autophagic dysfunction, which is essential for the enhanced therapeutic sensitivity of propranolol treatment. Taken together, our results indicated that PKM2 has a significant role in hemangiomas progression and therapeutic resistance; it could be a safe and effective therapeutic strategy for those hemangiomas with poor propranolol sensitivity combined with shikonin.


Asunto(s)
Hemangioma , Neoplasias Cutáneas , Animales , Propranolol/farmacología , Especies Reactivas de Oxígeno , Piruvato Quinasa , Células Endoteliales/patología , Antagonistas Adrenérgicos beta/uso terapéutico , Hemangioma/tratamiento farmacológico , Resultado del Tratamiento , Neoplasias Cutáneas/tratamiento farmacológico
12.
Chemistry ; 29(35): e202300882, 2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37069325

RESUMEN

Heterogeneous photocatalysis is a promising approach for a wide range of hydrogenative reactions owing to the mild reaction conditions and the possibility of employing liquid hydrogen donors. Currently, the major interest is focused on the development of high performance photocatalyst materials and the expansion of reaction scope. An overview from a perspective of hydrogen donor and thus the related mechanistic understanding of the light-induced hydrogenative reactions is rare. Here, we have categorized the photocatalytic hydrogenative reactions by the type of employed liquid hydrogen donors (hydrocarbons and water), discussed the basic criteria of hydrogen abstraction from these donors, and elaborated the design strategy of the photocatalyst materials.


Asunto(s)
Hidrocarburos , Hidrógeno , Catálisis , Agua
13.
Am J Obstet Gynecol ; 229(2): 166.e1-166.e16, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-36649818

RESUMEN

BACKGROUND: Perinatal mood and anxiety disorders encompass a range of mental health disorders that occur during pregnancy and up to 1 year postpartum, affecting approximately 20% of women. Traditional risk factors, such as a history of depression and pregnancy complications including preeclampsia, are known. Their predictive utility, however, is not specific or sensitive enough to inform clinical decision-making or prevention strategies for perinatal mood and anxiety disorders. Better diagnostic and prognostic models are needed for early identification and referral to treatment. OBJECTIVE: This study aimed to determine if a panel of novel third-trimester plasma protein biomarkers in pregnant women can be used to identify those who have a high predisposed risk for perinatal mood and anxiety disorders within 3 months postpartum. STUDY DESIGN: We studied 52 women (n=34 with a risk for perinatal mood and anxiety disorders and n=18 controls) among whom mental health screening was conducted at 2 time points, namely in the third trimester and again at 3 months postdelivery. An elevated perinatal mood and anxiety disorder risk was identified by screening individuals with above-validated cutoffs for depression (Edinburgh Postnatal Depression Scale ≥12), anxiety (Overall Anxiety Severity and Impairment Scale ≥7), and/or posttraumatic stress disorder (Impact of Events Scale >26) at both time points. Plasma samples collected in the third trimester were screened using the aptamer-based SomaLogic SomaScan proteomic assay technology to evaluate perinatal mood and anxiety disorder-associated changes in the expression of 1305 protein analytes. Ingenuity Pathway Analysis was conducted to highlight pathophysiological relationships between perinatal mood and anxiety disorder-specific proteins found to be significantly up- or down-regulated in all subjects with perinatal mood and anxiety disorder and in those with perinatal mood and anxiety disorders and no preeclampsia. RESULTS: From a panel of 53 significant perinatal mood and anxiety disorder-associated proteins, a unique 20-protein signature differentiated perinatal mood and anxiety disorder cases from controls in a principal component analysis (P<.05). This protein signature included NCAM1, NRCAM, and NTRK3 that converge around neuronal signaling pathways regulating axonal guidance, astrocyte differentiation, and maintenance of GABAergic neurons. Interestingly, when we restricted the analysis to subjects without preeclampsia, a 30-protein signature differentiated perinatal mood and anxiety disorder cases from all controls without overlap on the principal component analysis (P<.001). In the nonpreeclamptic perinatal mood and anxiety disorder group, we observed increased expression of proteins, such as CXCL11, CXCL6, MIC-B, and B2MG, which regulate leucocyte migration, inflammation, and immune function. CONCLUSION: Participants with perinatal mood and anxiety disorders had a unique and distinct plasma protein signature that regulated a variety of neuronal signaling and proinflammatory pathways. Additional validation studies with larger sample sizes are needed to determine whether some of these molecules can be used in conjunction with traditional risk factors for the early detection of perinatal mood and anxiety disorders.


Asunto(s)
Depresión Posparto , Complicaciones del Embarazo , Femenino , Embarazo , Humanos , Trastornos de Ansiedad/diagnóstico , Trastornos de Ansiedad/psicología , Depresión/diagnóstico , Proteómica , Ansiedad/complicaciones , Complicaciones del Embarazo/psicología , Biomarcadores , Depresión Posparto/diagnóstico
14.
BMC Surg ; 23(1): 237, 2023 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-37580688

RESUMEN

BACKGROUND: To explore the impact of preoperative 3D printing on the fixation of posterior rib fractures utilizing a memory alloy embracing device of rib under thoracoscopy. METHODS: The enrolled patients were divided into the 3D printing (11 patients) and the non-3D printing (18 patients) groups, based on whether a 3D model of ribs was prepared prior to surgery. Analysis was conducted comparing the average fixation time per fracture, postoperative fixation loss, and poor reduction of fractured end between the two groups. RESULTS: The average fixation time of each fracture was 27.2 ± 7.7 min in the 3D printing group and 29.3 ± 8.2 min in the non-3D printing group, with no statistically significant difference observed between the two groups (P > 0.05). The incidence of poor fracture fixation in the 3D printing group was statistically lower than that in the non-3D printing group (12.9% vs. 44.7%, P < 0.05). Further stratified analysis revealed that the off-plate rate in the 3D printing group and the non-3D group was (3.2% vs. 12.8%, P > 0.05), and the dislocation rate of the fractured end was (9.7% vs. 31.9%, P < 0.05). CONCLUSIONS: The application of 3D printing technology to prepare the rib model before surgery is proves beneficial in reducing the occurrence of poor fixation of fractures and achieving precise and individualized treatment.


Asunto(s)
Fracturas de las Costillas , Humanos , Fracturas de las Costillas/cirugía , Estudios de Cohortes , Fijación Interna de Fracturas , Impresión Tridimensional , Costillas , Resultado del Tratamiento
15.
Angew Chem Int Ed Engl ; 62(22): e202302979, 2023 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-36988035

RESUMEN

Heterogeneous photocatalysis is effective for the selective synthesis of value-added chemicals at lab-scale, yet falls short of requirements for mass production (low cost and user friendliness). Here we report the design and fabrication of a modular tubular flow system embedded with replaceable photocatalyst membranes for scalable photocatalytic C-C, C-N homocoupling and hydrogenation reactions, which can be operated in either circular and continuous flow mode with high performance. The photocatalyst membranes almost fully occupy the volume of the reactor, thus enabling optimal absorption of the incident light. Additionally, the porous structured photocatalyst membranes facilitate the mass transfer of the reactants to efficiently use the active sites, resulting in 0th -order reaction kinetics and a high space-time yield compared to the batch reaction system at practical application levels and prolonged reaction times.

16.
Angew Chem Int Ed Engl ; 62(51): e202313313, 2023 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-37930876

RESUMEN

Heterogeneous catalytic ammoxidation provides an eco-friendly route for the cyanide-free synthesis of nitrile compounds, which are important precursors for synthetic chemistry and pharmaceutical applications. However, in general such a process requires high pressures of molecular oxygen at elevated temperatures to accelerate the oxygen reduction and imine dehydrogenation steps, which is highly risky in practical applications. Here, we report an electric field enhanced ammoxidation system using a supported Fe clusters catalyst (Fe/NC), which enables efficient synthesis of nitriles from the corresponding aldehydes under ambient air pressure at room temperature (RT). A synergistic effect between the external electric field and the Fe/NC catalyst promotes the ammonia activation and the dehydrogenation of the generated imine intermediates and avoids the unwanted backwards reaction to aldehydes. This electric field enhanced ammoxidation system presents high efficiency and selectivity for the conversion of a series of aldehydes under mild conditions with high durability, rendering it an attractive process for the green synthesis of nitriles with fragile functional groups.

17.
Angew Chem Int Ed Engl ; 62(23): e202302994, 2023 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-37013857

RESUMEN

Environmental-friendly halogenation of C-H bonds using abundant, non-toxic halogen salts is in high demand in various chemical industries, yet the efficiency and selectivity of laboratory available protocols are far behind the conventional photolytic halogenation process which uses hazardous halogen sources. Here we report an FeX2 (X=Br, Cl) coupled semiconductor system for efficient, selective, and continuous photocatalytic halogenation using NaX as halogen source under mild conditions. Herein, FeX2 catalyzes the reduction of molecular oxygen and the consumption of generated oxygen radicals, thus boosting the generation of halogen radicals and elemental halogen for direct halogenation and indirect halogenation via the formation of FeX3 . Recycling of FeX2 and FeX3 during the photocatalytic process enables the halogenation of a wide range of hydrocarbons in a continuous flow, rendering it a promising method for applications.

18.
BMC Vet Res ; 18(1): 186, 2022 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-35581595

RESUMEN

BACKGROUND: Extended-spectrum ß-lactamases (ESBL)-producing strains of Klebsiella pneumoniae remain a worldwide, critical clinical concern. However, limited information was available concerning ESBL-producing Klebsiella pneumoniae in giant pandas. The objective of this study was to characterize ESBL-producing Klebsiella pneumoniae isolates from captive giant pandas. A total of 211 Klebsiella pneumoniae isolates were collected from 108 giant pandas housed at the Chengdu Research Base of Giant Panda Breeding (CRBGP), China. Samples were screened for the ESBL-producing phenotype via the double-disk synergy test. RESULT: A total of three (1.42%, n = 3/211) ESBL-producing Klebsiella pneumoniae strains were identified, and characterization of ESBL-producing Klebsiella pneumoniae isolates were studied by the detection of ESBL genes and mobile genetic elements (MGEs), evaluation of antimicrobial susceptibility and detection of associated resistance genes. Clonal analysis was performed by multi-locus sequencing type (MLST). Among the three ESBL-producing isolates, different ESBL-encoding genes, including blaCTX-M, and blaTEM, were detected. These three isolates were found to carry MGEs genes (i.e., IS903 and tnpU) and antimicrobial resistance genes (i.e., aac(6')-Ib, aac(6')-I, qnrA, and qnrB). Furthermore, it was found that the three isolates were not hypermucoviscosity, resistant to at least 13 antibiotics and belonged to different ST types (ST37, ST290, and ST2640). CONCLUSION: Effective surveillance and strict infection control strategies should be implemented to prevent outbreaks of ESBL-producing Klebsiella pneumoniae in giant pandas.


Asunto(s)
Infecciones por Klebsiella , Ursidae , Animales , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/veterinaria , Klebsiella pneumoniae/genética , Pruebas de Sensibilidad Microbiana/veterinaria , Tipificación de Secuencias Multilocus/veterinaria , beta-Lactamasas/genética
19.
BMC Vet Res ; 18(1): 68, 2022 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-35144609

RESUMEN

BACKGROUND: The red panda has been classified as an endangered species due to the decreased number in the world and disease is considered as a great threat to the health and survival of the cubs in captivity. RESULTS: This study analyzed 32 red panda cub mortalities (15 females and 17 males, age less than two months) through gross necropsy, microbiological examination, and histopathological observation at the Chengdu Research Base of Giant Panda Breeding, China, during 2014-2020. The results showed that screenings for canine distemper virus, canine parvovirus, rotavirus and parasite infection were all negative, however bacteria such as Klebsiella pneumoniae, Proteus mirabilis, Escherichia coli, Enterococcus faecalis, Pseudomonas were isolated from the tissue samples of some cubs. The major causes of death were respiratory (43.75%) and digestive system disease (28.13%), followed by cardiovascular disease (12.5%) and neonatal stillbirths (9.38%). Renal system diseases and trauma were also detected, at lower incidence (one case for each). The mortality rate within 15 days of birth was 68.75% and gradually decreased with age, there was no significant difference in gender. CONCLUSION: This study can provide a scientific basis for the analysis of the cause of death among red panda cubs in captivity, so as to improve the survival rate, help build the captive population and further the ex-situ conservation management of this endangered species. Additionally, our research may also provide insights into the in-situ conservation of wild red pandas by identifying emerging disease threats within the wild population and potential treatment for rescued individuals.


Asunto(s)
Ailuridae , Virus del Moquillo Canino , Enfermedades de los Perros , Infecciones por Escherichia coli , Animales , China/epidemiología , Perros , Especies en Peligro de Extinción , Infecciones por Escherichia coli/veterinaria , Femenino , Masculino
20.
Angew Chem Int Ed Engl ; 61(24): e202204256, 2022 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-35334135

RESUMEN

Employing pure water, the ultimate green source of hydrogen donor to initiate chemical reactions that involve a hydrogen atom transfer (HAT) step is fascinating but challenging due to its large H-O bond dissociation energy (BDEH-O =5.1 eV). Many approaches have been explored to stimulate water for hydrogenative reactions, but the efficiency and productivity still require significant enhancement. Here, we show that the surface hydroxylated graphitic carbon nitride (gCN-OH) only requires 2.25 eV to activate H-O bonds in water, enabling abstraction of hydrogen atoms via dehydrogenation of pure water into hydrogen peroxide under visible light irradiation. The gCN-OH presents a stable catalytic performance for hydrogenative N-N coupling, pinacol-type coupling and dehalogenative C-C coupling, all with high yield and efficiency, even under solar radiation, featuring extensive impacts in using renewable energy for a cleaner process in dye, electronic, and pharmaceutical industries.

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