Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 439
Filter
1.
Inorg Chem ; 63(16): 7504-7511, 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38598777

ABSTRACT

Lamellar metal-organic frameworks (MOFs) have attracted significant attention in the field of electrochemical sensing due to their abundant open active sites and specific electron conductivity. Herein, by employing a bottom-up synthesis strategy, rhombic lamellar heterometallic CoNi-MOFs with varying thicknesses are constructed. This is achieved by using 4-methylpyridine as a capping agent based on the (4,6)-linked Co2(azpy)2(bptc) (azpy = 4,4'-azopyridine, bptc = 3,3',5,5'-biphenyltetracarboxylic acid) structure with a fsc topology and by introducing Ni species simultaneously. To mitigate sulfur deposition on electrodes, the triple pulse amperometry (TPA) method is employed. Among the synthesized lamellar CoNi-MOFs, lamellar CoNi-MOF-3 with the minimum thickness exhibits an optimal electrochemical sensing performance toward hydrogen sulfide, with a sensitivity of 119.3 µA·mM-1·cm-2 in the linear range of 2-2000 µM. This study pioneers a new approach to the controlled construction and electrochemical activity modification of lamellar MOF materials.

2.
Mater Horiz ; 11(8): 1957-1963, 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38348621

ABSTRACT

Fixation of CO2 into dihydroisobenzofuran derivatives has enormous applications in both production of natural products and antidepressant drugs, and reducing the green-house effect. However, the relatively complicated multi-step processes limit the further expansion of such a valuable CO2 conversion strategy. Herein, we hierarchically modify the surface of Cu nanoparticles (NPs) with Ag NPs and the robust metal-organic framework (MOF), ZIF-8, and report the presence of the Cu-Ag yolk-shell nanoalloy based heterogeneous catalysts, Cu@Ag and Cu@Ag@ZIF-8. The latter exhibits a crystalline "raisin bread" structure and specific synergic activity for catalyzing the tandem reactions of intra-molecular H-transfer, C-C and C-O coupling, cyclization, and carboxylation from CO2, leading to the first non-homogeneous preparation of dihydroisobenzofuran derivatives in high yield, selectivity, and recyclability under mild conditions. Theoretical calculations elucidate the tandem reaction pathway synergically catalyzed by Cu@Ag@ZIF-8, which offers insights for designing multiphase catalysts towards both organic synthesis and CO2 fixation through tandem processes in one pot.

3.
Biomed Pharmacother ; 173: 116262, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38394845

ABSTRACT

BACKGROUND: The glucose derivative 3-O-methyl-D-glucose (OMG) is used as a cryoprotectant in freezing cells. However, its protective role and the related mechanism in static cold storage (CS) of organs are unknown. The present study aimed to investigate the effect of OMG on cod ischemia damage in cold preservation of donor kidney. METHODS: Pretreatment of OMG on kidney was performed in an isolated renal cold storage model in rats. LDH activity in renal efflux was used to evaluate the cellular damage. Indicators including iron levels, mitochondrial damage, MDA level, and cellular apoptosis were measured. Kidney quality was assessed via a kidney transplantation (KTx) model in rats. The grafted animals were followed up for 7 days. Ischemia reperfusion (I/R) injury and inflammatory response were assessed by biochemical and histological analyses. RESULTS: OMG pretreatment alleviated prolonged CS-induced renal damage as evidenced by reduced LDH activities and tubular apoptosis. Kidney with pCS has significantly increased iron, MDA, and TUNEL+ cells, implying the increased ferroptosis, which has been partly inhibited by OMG. OMG pretreatment has improved the renal function (p <0.05) and prolonged the 7-day survival of the grafting recipients after KTx, as compared to the control group. OMG has significantly decreased inflammation and tubular damage after KTx, as evidenced by CD3-positive cells and TUNEL-positive cells. CONCLUSION: Our study demonstrated that OMG protected kidney against the prolonged cold ischemia-caused injuries through inhibiting ferroptosis. Our results suggested that OMG might have potential clinical application in cold preservation of donor kidney.


Subject(s)
Ferroptosis , Reperfusion Injury , Rats , Animals , 3-O-Methylglucose/pharmacology , Cold Ischemia/adverse effects , Organ Preservation/methods , Kidney , Reperfusion Injury/prevention & control , Reperfusion Injury/pathology , Ischemia/pathology , Iron
4.
J Asian Nat Prod Res ; 26(1): 4-17, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37888783

ABSTRACT

Seven new monoterpene alkaloids (1 - 7), along with 16 known analogues, were isolated from an aqueous decoction of the hook-bearing stems of Uncaria rhynchophylla (Gou-teng). Their structures were determined by spectroscopic data analysis, single crystal X-ray diffraction, and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 are stereoisomers belonging to a novel type of pseudoindoxyl monoterpene alkaloids, 3 is the first monoterpene furoindole alkaloid from nature, and 4 - 7 are derivatives of the known monoterpene alkaloids featuring different structures.


Subject(s)
Alkaloids , Uncaria , Indole Alkaloids/chemistry , Uncaria/chemistry , Monoterpenes
5.
Cryst Growth Des ; 23(7): 5211-5220, 2023 Jul 05.
Article in English | MEDLINE | ID: mdl-37426545

ABSTRACT

Chiral metal-organic materials (CMOMs), can offer molecular binding sites that mimic the enantioselectivity exhibited by biomolecules and are amenable to systematic fine-tuning of structure and properties. Herein, we report that the reaction of Ni(NO3)2, S-indoline-2-carboxylic acid (S-IDECH), and 4,4'-bipyridine (bipy) afforded a homochiral cationic diamondoid, dia, network, [Ni(S-IDEC)(bipy)(H2O)][NO3], CMOM-5. Composed of rod building blocks (RBBs) cross-linked by bipy linkers, the activated form of CMOM-5 adapted its pore structure to bind four guest molecules, 1-phenyl-1-butanol (1P1B), 4-phenyl-2-butanol (4P2B), 1-(4-methoxyphenyl)ethanol (MPE), and methyl mandelate (MM), making it an example of a chiral crystalline sponge (CCS). Chiral resolution experiments revealed enantiomeric excess, ee, values of 36.2-93.5%. The structural adaptability of CMOM-5 enabled eight enantiomer@CMOM-5 crystal structures to be determined. The five ordered crystal structures revealed that host-guest hydrogen-bonding interactions are behind the observed enantioselectivity, three of which represent the first crystal structures determined of the ambient liquids R-4P2B, S-4P2B, and R-MPE.

6.
Int J Public Health ; 68: 1606091, 2023.
Article in English | MEDLINE | ID: mdl-37465051

ABSTRACT

Objectives: To explore the utilization, barriers, and factors associated with the targeted treatment of Chinese metastatic colorectal cancer (mCRC) patients. Methods: A total of 1,688 mCRC patients from 19 hospitals in 14 cities were enrolled from March 2020 to March 2021 using stratified, multistage cluster sampling. The use of targeted therapy and any barriers patients experienced were collected. Logistic regression analyses were conducted to identify the factors associated with initiating targeted treatment. Results: About 51.6% of the patients initiated targeted therapy, of whom 44.5%, 20.2%, and 35.2% started first-, second-, and third-line treatment, respectively. The most reported barriers were high medical costs and a lack of belief in the efficacy of targeted therapy. Patients treated in the general hospital, diagnosed at an older age, less educated, and who had a lower family income, no medical insurance, poor health-related quality of life, metastasis outside the liver/lung or systemic metastasis, a shorter duration of mCRC were less likely to initiate targeted therapy. Conclusion: Reduced medical costs and interventional education to improve public awareness could facilitate the use of targeted treatment for mCRC.


Subject(s)
Colonic Neoplasms , Colorectal Neoplasms , Humans , Colorectal Neoplasms/drug therapy , Quality of Life , Costs and Cost Analysis , Hospitals
7.
Adv Sci (Weinh) ; 10(26): e2302881, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37394727

ABSTRACT

Catalytic conversion of CO2 into high value-added chemicals using renewable energy is an attractive strategy for the management of CO2 . However, achieving both efficiency and product selectivity remains a great challenge. Herein, a brand-new family of 1D dual-channel heterowires, Cu NWs@MOFs are constructed by coating metal-organic frameworks (MOFs) on Cu nanowires (Cu NWs) for electro-/photocatalytic CO2 reductions, where Cu NWs act as an electron channel to directionally transmit electrons, and the MOF cover acts as a molecule/photon channel to control the products and/or undertake photoelectric conversion. Through changing the type of MOF cover, the 1D heterowire is switched between electrocatalyst and photocatalyst for the reduction of CO2 with excellent selectivity, adjustable products, and the highest stability among the Cu-based CO2 RR catalysts, which leads to heterometallic MOF covered 1D composite, and especially the first 1D/1D-type Mott-Schottky heterojunction. Considering the diversity of MOF materials, the ultrastable heterowires offer a highly promising and feasible solution for CO2 reduction.

8.
Sci Adv ; 9(24): eadh0198, 2023 Jun 16.
Article in English | MEDLINE | ID: mdl-37315147

ABSTRACT

Transition metal complexes exhibiting thermally activated delayed fluorescence (TADF) remain underdeveloped for organic light-emitting diodes (OLEDs). Here, we describe a design of TADF Pd(II) complexes featuring metal-perturbed intraligand charge-transfer excited states. Two orange- and red-emitting complexes with efficiencies of 82 and 89% and lifetimes of 2.19 and 0.97 µs have been developed. Combined transient spectroscopic and theoretical studies on one complex reveal a metal-perturbed fast intersystem crossing process. OLEDs using the Pd(II) complexes show maximum external quantum efficiencies of 27.5 to 31.4% and small roll-offs down to 1% at 1000 cd m-2. Moreover, the Pd(II) complexes show exceptional operational stability with LT95 values over 220 hours at 1000 cd m-2, benefiting from the use of strong σ-donating ligands and the presence of multiple intramolecular noncovalent interactions beside their short emission lifetimes. This study demonstrates a promising approach for developing efficient and robust luminescent complexes without using the third-row transition metals.

9.
Inorg Chem ; 62(26): 10382-10388, 2023 Jul 03.
Article in English | MEDLINE | ID: mdl-37348470

ABSTRACT

Based on benzo[i]dipyrido[3,2-a:2',3'-c]phenazine (dppn) with photo-oxidation activity, complexes [Ir(pbt)2(dppn)]Cl (1) and [Ir(pt)2(dppn)]Cl (2) have been synthesized (pbtH = 2-phenylbenzothiazole, and ptH = 2-phenylthiazole), with two aims, including studying the influence of the cyclometalating ligands (pbt- in 1, pt- in 2) on the photo-oxidation activity of these complexes and exploring their photo-oxidation-induced luminescence. Both 1H nuclear magnetic resonance (NMR) and electrospray (ES) mass spectrometry indicate that the benzo[g]quinoxaline moiety in complex 1 can be oxidized at room temperature upon irradiation with 415 nm light. Thus, this complex in CH2Cl2 shows photo-oxidation-induced turn-on yellow luminescence. In contrast, complex 2 reveals significant structural decomposition during the process of photo-oxidation due to incorporating a cyclometalating ligand pt- instead of pbt- in complex 1. In this paper, we report the photo-oxidation behaviors and the related luminescence modulation in 1 and 2 and discuss the relationship between structure and photo-oxidation activity in these complexes.

10.
Am J Health Behav ; 47(1): 165-172, 2023 02 28.
Article in English | MEDLINE | ID: mdl-36945091

ABSTRACT

Objectives: In this study, we analyzed negative online public opinion in tertiary hospitals and evaluated corresponding risk by applying the Kaiser Model. Methods: Through data and expert group discussion, combined with the hospital's actual negative online public opinion management, we determined the opinions posing higher risk. The hospital's risk questionnaire for negative opinion was designed based on the Kaiser Model. The whole hospital staff was then trained and investigated. An Excel worksheet was used for statistical analysis and risk calculation.Results: According to the ranking of risk value, the top 5 negative online public opinions were drug supply and demand, in-hospital parking, handling of public health emergencies, the service attitude of hospital guidance staff, and interpretation of medical insurance policies. Conclusion: The hospital needs to revise and improve the emergency response plan for negative online public opinion based on the analysis results and reports of opinion risks. This is helpful for strengthening hospital-level emergency training, improving the hospital's ability to manage negative opinion risks, and promoting the hospital to become passive about negative online public opinion.


Subject(s)
Public Opinion , Risk Management , Humans , Tertiary Care Centers , Public Health , Surveys and Questionnaires
11.
J Asian Nat Prod Res ; 25(10): 919-940, 2023 Oct.
Article in English | MEDLINE | ID: mdl-36748290

ABSTRACT

Neolignans and lignans with diverse new chemical structures, including eleven pairs of separated chiral enantiomers [(+)-/(-)-1-(+)-/(-)-5, (+)-/(-)-8, (+)-/(-)-10, and (+)-/(-)-12-(+)-/(-)-15], two achiral compounds (6 and 9), and an unseparated racemate [(±)-11], together with a new natural product (7) and 21 known derivatives, were isolated from an aqueous extract of the Angelica sinensis root head (guitou). Among the chiral isolates, (+)-/(-)-13 and (+)-/(-)-15 were scalemic pairs with enantiomeric ratios of around 3:1 and 1.5:1, respectively, while others were enantiomeric equivalent pairs. This indicates that the diverse neolignans in A. sinensis are biosynthesized via different pathways with varying degrees of stereo-controlled manners.


Subject(s)
Angelica sinensis , Drugs, Chinese Herbal , Lignans , Lignans/chemistry , Stereoisomerism
12.
ChemSusChem ; 16(7): e202201974, 2023 Apr 06.
Article in English | MEDLINE | ID: mdl-36588092

ABSTRACT

The widespread use of chemicals has brought serious water pollution threatening human health and environment, which requires green, fast, and low-cost purification urgently. Here, we build up a novel material family of sky-parking-like 3D structured graphene oxides (SP-GOs) with adjustable interlayer-space of 0.8-1.7 nm via the insertion of different sized diamine compounds as support pillars between GO layers. The assembled 3D SP-GOs exhibit superior adsorption capacity and short removal time for various aromatic organic compounds in water, achieving record-breaking maximum adsorption capacity of 535.79 mg g-1 toward the most common water-pollutant bisphenol A (BPA) at ambient conditions as well as significantly improved removal of other organic pollutants including sulfapyridine, carbamazepine, ketoprofen and 2-naphthol. The construction of SP-GO provides a simple approach for evolving the GO material from 2D to 3D and a new avenue for the decontamination of pollutants in environmental remediation.

13.
Angew Chem Int Ed Engl ; 62(8): e202217662, 2023 Feb 13.
Article in English | MEDLINE | ID: mdl-36585907

ABSTRACT

Two C2 H6 -selective metal-organic framework (MOF) adsorbents with ultrahigh stability, high surface areas, and suitable pore size have been designed and synthesized for one-step separation of ethane/ethylene (C2 H6 /C2 H4 ) under humid conditions to produce polymer-grade pure C2 H4 . Experimental results reveal that these two MOFs not only adsorb a high amount of C2 H6 but also display good C2 H6 /C2 H4 selectivity verified by fixed bed column breakthrough experiments. Most importantly, the good water stability and hydrophobic pore environments make these two MOFs capable of efficiently separating C2 H6 /C2 H4 under humid conditions, exhibiting the benchmark performance among all reported adsorbents for separation of C2 H6 /C2 H4 under humid conditions. Moreover, the affinity sites and their static adsorption energies were successfully revealed by single crystal data and computation studies. Adsorbents described in this work can be used to address major chemical industrial challenges.

15.
Acta Pharmaceutica Sinica ; (12): 2734-2745, 2023.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-999015

ABSTRACT

Four new triterpenoids, together with six known analogues, were isolated from an aqueous extract of the Ziziphus jujuba var. spinosa seeds, by multiple column chromatographic separation methods using stationary phases of macroporous adsorption resin, MCI resin, normal phase silica gel, Sephadex LH-20, and Toyopearl HW-40C as well as preparative thin-layer chromatography and reversed-phase HPLC. Their structures were determined by spectroscopic data analysis, the new structures were trivially named jujubaceanothoside A (1), 23-epijujuboside A (2), and jujubosides J and K (3 and 4), while the known analogues were identified as jujubosides A-C (5-7) and II (8), alphitolic acid (9), and betulinic acid (10). The structure of 1 was confirmed by single crystal X-ray diffraction.

16.
Acta Pharmaceutica Sinica ; (12): 3701-3709, 2023.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-1004645

ABSTRACT

Twelve compounds, including 5 new monoterpenes and 7 known derivatives, were isolated from a water decoction of Monochasma savatieri by column chromatography over macroporous adsorbent resin, MCI resin, Sephadex LH-20, and HW-40C, combined with preparative TLC, reversed phase HPLC, and flash column chromatographic techniques. Their structures were elucidated by comprehensive analysis of spectroscopic data, along with enzymatic hydrolysis as well as electronic circular dichroism (ECD) and NMR calculations, the new structures named monochaside I (1) and monochairidols A-D (2-5), respectively. The known compounds 6-12 were obtained from the Monochasma plants for the first time.

17.
Acta Pharmaceutica Sinica ; (12): 992-1002, 2023.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-978771

ABSTRACT

Seventeen minor triterpenoid acids (1-17) were isolated from an aqueous decoction of Uncaria rhynchophylla by a combinatory application of column chromatography using multiple stationary phases, including macroporous adsorbent resin, MCI resin, Sephadex LH-20, Toyopearl HW-40C, silica gel, and C18 reversed phase silica gel, combined with separation techniques of flash chromatography (FC) and high performance liquid chromatography (HPLC). Their structures were determined by analysis of HR-ESI-MS, UV, CD, and IR as well as 1D and 2D NMR spectroscopic data, of which eight new compounds (1-8) are named successively uncarinic acids Q-X, while the structures of 2 and 7 were confirmed by single crystal X-ray diffraction. In the in vitro assays, 27-hydroxyolean-12-en-28-oic acid (17) inhibited TGF-β-induced HSC-T6 cell activation at the concentration of 5 μmol·L-1.

18.
Acta Pharmaceutica Sinica ; (12): 975-991, 2023.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-978770

ABSTRACT

Ten dimeric phthalide racemates (1-10) were isolated from an aqueous extract of the Angelica sinensis root head (Guitou) by separation techniques of column chromatography over macroporous adsorbent resin, MCI resin, silica gel, and Sephadex LH-20, together with preparative thin-layer chromatography and reversed phase HPLC. The racemates were further separated into (+)-/(-)-1-(+)-/(-)-10 with chiral HPLC. Their structures including absolute configurations were elucidated by comprehensive analysis of spectroscopic data, combined with electronic circular dichroism (ECD) and NMR calculations as well as single crystal X-ray diffractions. Compounds (+)-/(-)-1-(+)-/(-)-10 are either new structure or new natural product, named (+)-/(-)-angelidipthalidic acids A-H [(+)-/(-)-1-(+)-/(-)-8] and (+)-/(-)-angelidipthalidols A and B [(+)-/(-)-9 and (+)-/(-)-10], respectively. Meanwhile, dimeric phthalide mono- and bis-lactone derivatives with 3.3′a,8.6′- and 3.6′,8.3′a-coupling patterns as well as determination of their relative configurations are discussed.

19.
Acta Pharmaceutica Sinica ; (12): 1641-1649, 2023.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-978731

ABSTRACT

Eleven monoterpenes including seven new chemical structures or new natural products covering two pairs of scalemic enantiomers, together with four known analogues, were isolated from an aqueous extract of the Angelica sinensis root head (Guitou) by separation techniques of column chromatography over macroporous adsorbent resin, MCI resin, silica gel, Sephadex LH-20, and Toyopearl HW-40C, together with preparative thin-layer chromatography as well as reversed phase and chiral HPLC. Their structures were determined by spectroscopic data analysis, combined with theoretic calculation of electronic circular dichroism (ECD) spectra and single crystal X-ray diffraction. The new structures or new natural products named (+)-/(-)-angelinones A and B [(+)-/(-)-1 and (+)-/(-)-2], angelinones C and D (3 and 4), and angelinol A (5), respectively, while the known analogues were 6β,9-dihydroxy-(+)-α-pinene (6), 1,1,5-trimethyl-2-hydroxymethyl-cyclohexa-2,5-dien-4-one (7), jasminol E (8), and (+)-trans-sobrerol (9). All the isolates were reported in this plant for the first time, except for the previously reported 6 from an ethanol extract of the aerial parts of A. sinensis, of which the structure was confirmed by X-ray crystallography in this study.

20.
Front Endocrinol (Lausanne) ; 13: 1056327, 2022.
Article in English | MEDLINE | ID: mdl-36465639

ABSTRACT

Since Costello et al. proposed the concept of pseudocapsule of pituitary neuroendocrine tumors (PitNETs) in 1936, many studies have been published on its occurrence, development process, histopathology, and morphology. Pseudocapsule has been proposed as the anatomical interface between PitNETs and normal pituitary gland, therefore the so-called pseudocapsule-based extracapsular resection (ER) technique was developed as an extracapsular surgery method for PitNETs,which differs from the conventional intracapsular resection (IR). In recent years, ER has also been widely used in patients of different tumor types, sizes, and age groups, because the pseudocapsule can be identified more clearly under the endoscopy. Endoscopic transsphenoidal resection for PitNETs has become the preferred surgical method. We reviewed relevant literatures in the past 10 years, showing that ER could achieve better rate of gross total resection (GTR) and biochemical remission, and reduce tumor recurrence than IR, without increasing postoperative complications. Therefore, the pseudocapsule and ER should be valued by neurosurgeons and actively promoted clinically.


Subject(s)
Neuroendocrine Tumors , Pituitary Diseases , Pituitary Neoplasms , Humans , Neuroendocrine Tumors/surgery , Pituitary Gland , Pituitary Neoplasms/surgery , Neurosecretory Systems
SELECTION OF CITATIONS
SEARCH DETAIL
...