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1.
Am J Case Rep ; 25: e944782, 2024 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-39152632

RESUMO

BACKGROUND The tip-flexible suctioning ureteral access sheath (TFS-UAS) can be bent under flexible ureteroscopes, which facilitates removal of renal stone segments by irrigation and suctioning effects. Small-scale comparative studies found it safer and more efficacious than traditional UAS. However, complications such as renal abscess were not documented after TFS-UAS combined with digital FURS. CASE REPORT A 57-year-old woman had right lumbar pain that persisted for 1 year. A plain computed tomography (CT) scan revealed multiple renal pelvicalyceal stones (maximum diameter 20×9 mm). She was admitted to undergo elective surgery with a TFS-UAS combined with digital flexible ureteroscopic lithotripsy. The operation was deemed successful and she was given postoperative antibiotics for 2 days before discharge. Eight postoperative days later, she was admitted to the emergency department due to high fever (39.6°C). Plain CT revealed intact double-J stents and no abnormalities. She was readmitted to the urological department to receive antibiotic therapy, which progressed to septic shock (blood pressure 80/50 mmHg) and required immediate transfer to the intensive care unit. Contrast-enhanced CT revealed a right renal abscess. She was promptly resuscitated and given stronger antibiotics. She recovered well and was discharged with 2-week oral levofloxacin treatment. Follow-up ultrasound found no renal abscess. CONCLUSIONS While TFS-UAS with digital FURs is an effective approach for multiple renal stones, there is a risk of postoperative renal abscess, possibly due to altered intrarenal pressure.


Assuntos
Abscesso , Cálculos Renais , Litotripsia , Ureteroscopia , Humanos , Feminino , Pessoa de Meia-Idade , Ureteroscopia/efeitos adversos , Litotripsia/efeitos adversos , Cálculos Renais/cirurgia , Abscesso/etiologia , Abscesso/terapia , Sucção , Complicações Pós-Operatórias , Nefropatias
2.
Transl Androl Urol ; 13(5): 828-832, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38855587

RESUMO

Percutaneous nephrolithotomy (PCNL) is the primary choice for managing large renal stones and the establishment of mini-/micro-channels has been increasingly gaining practice. The smaller the channel, the easier it is to be lost, which may require a new puncture site and increase the risk of bleeding complications. In this study, we retrospectively reviewed 1,056 PCNL procedures in our single institute, The University of Hong Kong - Shenzhen Hospital, between March 2014 and August 2023. Twenty-three cases of nephrostomy channel loss during mini PCNL were identified, resulting in an incidence rate of 2.2%. Methylene blue was immediately injected into the ureteral catheter to facilitate location and retrieval of the channel. Once extravasation of the dye was identified under rigid ureteroscope, a first guidewire was introduced into the channel for maintenance, followed by another guidewire inserted in parallel to facilitate dilatation. The major reasons for PCNL channel loss were mild hydronephrosis and complete obstruction of the target calyx due to renal stones. Technical success, defined as the ability to retrieve the lost channel within 5 minutes, was 78.3% (n=18/23). Three channels were completely lost and 2 patients showed channel bleeding despite successful identification, all of which required establishment of a new PCNL channel. No major intraoperative nor postoperative complication was observed.

3.
Transl Androl Urol ; 13(1): 185-191, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38404560

RESUMO

Background: Percutaneous nephrolithotomy (PCNL) is the first-line treatment for large renal stones. However, multi-tract or staged procedures may be necessitated in bilateral or anatomically-complex stones to achieve stone clearance. Endoscopic combined intrarenal surgery (ECIRS) integrates the advantages of PCNL and retrograde intrarenal surgery. In this article, we detail a hybrid surgical technique adopted for the management of complex simultaneous bilateral upper urinary tract stones. In addition, we discuss the advantages and disadvantages of combining a variety of new techniques that may improve post-operative outcomes and patient satisfaction. Case Description: We report the case of a 36-year-old male with a large left renal pelvis stone, right proximal ureteric stone, and bilateral renal stones. Biochemical results showed raised inflammatory markers but he denied pre-stenting and staged surgery. After receiving 3-day antibiotic prophylaxis, he underwent an elective hybrid procedure. Under split-leg prone position, we performed a hybrid procedure that included left ECIRS with tubeless single-tract mini PCNL and left flexible ureteroscopy, and right flexible ureteroscopic lithotripsy. Hemostasis was achieved by electrocauterization with a novel device. The patient made an uneventful recovery. Follow-up computed tomography (CT) at 1-month revealed complete stone clearance. Conclusions: Unilateral ECIRS with tubeless single-tract mini PCNL with electrocoagulation hemostasis and adjacent retrograde intrarenal surgery in split-leg prone position is a safe, feasible, and efficient technique to manage large renal stones.

4.
Curr Mol Med ; 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38178660

RESUMO

BACKGROUND: Neuroblastoma (NB) is one of the most common pediatric solid tumors. Emerging evidence has indicated that ADGRL4 can act as a master regulator of tumor progression. In addition, it is well documented that the ERK/STAT3 signaling pathway can promote the proliferation, EMT, angiogenesis, and metastasis in tumors. The current study was formulated to elucidate the exact role of ADGRL4 in the malignant behaviors of NB cells and to investigate the intrinsic mechanism. METHODS: In this work, expression differences of ADGRL4 in human NB cell lines and HUVECs were assessed via RT-qPCR and western blot analysis. For functional experiments, sh-ADGRL4 was transfected into SK-N-SH cells to generate ADGRL4 knockdown stable cell line. Moreover, ADGRL4 knockdown stable SK-N-SH cells were treated with LM22B-10 (an ERK activator) for rescue experiments. CCK-8 colony formation determined NB cells' growth, migration, invasion, wound healing, and transwell assays. Meanwhile, proliferation-, metastasis- and EMT- associated proteins were also detected. Additionally, a tube formation assay was employed to evaluate in vitro angiogenesis. VM-cadherin, the marker of angiogenesis, was assessed using immunofluorescence staining. RESULTS: Data showed notably upregulated ADGRL4 in NB cells, especially in SK-NSH cells. ADGRL4 knockdown inhibited NB cell growth, migration, invasion, EMT, and in vitro angiogenesis. ADGRL4 knockdown inactivated ERK/STAT3 signaling pathway. Activation of the ERK/STAT3 signaling pathway partially rescued the tumor suppression effects of ADGRL4 knockdown on NB cells. CONCLUSION: To conclude, the downregulation of ADGRL4 may inhibit cell growth, aggressiveness, EMT, and angiogenesis in NB by inactivating the ERK/STAT3 signaling pathway.

5.
Pol J Pathol ; 74(3): 182-193, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37955537

RESUMO

S100 calcium-binding protein A16 (S100A16) has previously been reported to play a role in tumor cells. Nevertheless, the role that S100A16 played in nephroblastoma cells remains obscure. The expression of S100A16 and DEPDC1 were detected via RT-q PCR and western blotting. Cell transfection was performed to overexpress DEPDC1 or interfere S100A16. CCK8 was applied for the assessment of cell viability. The apoptotic level and the capabilities of WiT49 cells to proliferate, invade and migrated were appraised utilizing Tunel, colony formation Transwell, and wound healing, separately. The angiogenesis was estimated through tube formation assay. Co-immunoprecipitation (CO-IP) was performed to examine the targeted binding of S100A16 to DEPDC1. The contents of PI3K/Akt/mTOR pathway-related proteins were resolved by virtue of western blot. S100A16 and DEPDC1 expression levels were significantly increased in nephroblastoma cell lines. S100A16 deletion suppressed nephroblastoma cell proliferative, invasive, migrative and angiogenetic capabilities but facilitated the apoptotic level. Moreover, S100A16 could bind DEPDC1, DEPDC1 overexpression partially reversed the inhibitory effect of S100A16 interference on nephroblastoma cell. DEPDC1 overexpression also partially counteracted the suppressive impacts of S100A16 interference on PI3K/Akt/mTOR pathway-related proteins. S100A16 synergistic with DEPDC1 promotes the progression and angiogenesis of nephroblastoma cell through the PI3K/Akt/mTOR pathway.


Assuntos
Proteínas Proto-Oncogênicas c-akt , Tumor de Wilms , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Linhagem Celular Tumoral , Serina-Treonina Quinases TOR/metabolismo , Tumor de Wilms/genética , Proteínas de Neoplasias/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Proteínas S100/metabolismo
6.
Cancer Imaging ; 23(1): 112, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37978567

RESUMO

BACKGROUND: To predict the microvascular invasion (MVI) in patients with cHCC-ICC. METHODS: A retrospective analysis was conducted on 119 patients who underwent CT enhancement scanning (from September 2006 to August 2022). They were divided into MVI-positive and MVI-negative groups. RESULTS: The proportion of patients with CEA elevation was higher in the MVI-positive group than in the MVI-negative group, with a statistically significant difference (P = 0.02). The MVI-positive group had a higher rate of peritumoral enhancement in the arterial phase (P = 0.01) whereas the MVI-negative group had more oval and lobulated masses (P = 0.04). According to the multivariate analysis, the increase in CEA (OR = 10.15, 95% CI: 1.11, 92.48, p = 0.04), hepatic capsular withdrawal (OR = 4.55, 95% CI: 1.44, 14.34, p = 0.01) and peritumoral enhancement (OR = 6.34, 95% CI: 2.18, 18.40, p < 0.01) are independent risk factors for predicting MVI. When these three imaging signs are combined, the specificity of MVI prediction was 70.59% (series connection), and the sensitivity was 100% (parallel connection). CONCLUSIONS: Our multivariate analysis found that CEA elevation, liver capsule depression, and arterial phase peritumoral enhancement were independent risk factors for predicting MVI in cHCC-ICC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/irrigação sanguínea , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/irrigação sanguínea , Estudos Retrospectivos , Microvasos/diagnóstico por imagem , Invasividade Neoplásica , Tomografia Computadorizada por Raios X
7.
Sensors (Basel) ; 23(17)2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37687962

RESUMO

Mobile sensors can extend the range of monitoring and overcome static sensors' limitations and are increasingly used in real-life applications. Since there can be significant errors in mobile sensor localization using the Monte Carlo Localization (MCL), this paper improves the food digestion algorithm (FDA). This paper applies the improved algorithm to the mobile sensor localization problem to reduce localization errors and improve localization accuracy. Firstly, this paper proposes three inter-group communication strategies to speed up the convergence of the algorithm based on the topology that exists between groups. Finally, the improved algorithm is applied to the mobile sensor localization problem, reducing the localization error and achieving good localization results.

8.
Angew Chem Int Ed Engl ; 62(37): e202306849, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37469101

RESUMO

Accurate identifying and in-depth understanding of the defect sites in a working nanomaterial could hinge on establishing specific defect-activity relationships. Yet, atomically precise coinage-metal nanoclusters (NCs) possessing surface vacancy defects are scarce primarily owing to challenges in the synthesis and isolation of such defective NCs. Herein we report a mixed-ligand strategy to synthesizing an intrinsically chiral and metal-deficient copper hydride-rich NC [Cu57 H20 (PET)36 (TPP)4 ]+ (Cu57 H20 ). Its total structure (including hydrides) and electronic structure are well established by combined experimental and computational results. Crystal structure reveals Cu57 H20 features a cube-like Cu8 kernel embedded in a corner-missing metal-ligand shell of Cu49 (PET)36 (TPP)4 . Single Cu vacancy defect site occurs at one corner of the shell, evocative of mono-lacunary polyoxometalates. Theoretical calculations demonstrate that the above-mentioned point vacancy causes one surface hydride exposed as an interfacial capping µ3 -H- , which is accessible in chemical reaction, as proved by deuterated experiment. Moreover, Cu57 H20 shows catalytic activity in the hydrogenation of nitroarene. The success of this work opens the way for the research on well-defined chiral metal-deficient Cu and other metal NCs, including exploring their application in asymmetrical catalysis.

9.
Urol Case Rep ; 50: 102500, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37484193

RESUMO

Gas-containing renal stones (GCS) are rare urological entities. Current literature has suggested possible associations with premenopausal women, urinary tract infection, and metabolic diseases. We report the case of a 25-year-old young woman with no underlying co-morbidities who had multiple right GCS and suspected emphysematous pyelitis. Antibiotic therapy was initiated to control her urinary tract infection with E. coli. She then underwent elective right flexible ureteroscopy to relieve her ureteropelvic junction obstruction. Complete stone retrieval was achieved and she made an uneventful recovery with no stone recurrence during 1-year follow-up.

10.
Am J Case Rep ; 24: e939700, 2023 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-37270666

RESUMO

BACKGROUND Percutaneous nephrolithotomy (PCNL) is indicated for large renal calculi (≥2 cm) and is often the treatment of choice due to its high success rate. Guidewire fragmentation is a rare procedural accident that can occur in PCNL but may be missed. Retention of the fragment within the upper urinary tract can lead to further complications, such as recurrent nephrolithiasis or impairment of renal function. CASE REPORT We present the case of a 54-year-old man who experienced right flank pain for 5 days. His history was significant for recurrent nephrolithiasis, managed by PCNL in other hospitals. The most recent procedure was conducted 4 years ago, and his perioperative course was uneventful. Preoperative computed tomography revealed right renal calculi and a C-shaped foreign body. He was scheduled for an elective PCNL. The foreign body was intraoperatively identified as a guidewire fragment and removed. CONCLUSIONS Currently, there is no standard management for intrarenal foreign bodies. Suspicion should be raised in young patients with recurrent stones within a short period of time. A thorough history on past urological interventions should be obtained. Symptoms can also have an insidious onset that could mimic nephrolithiasis or urinary tract infections. Extraction can be done via a standard minimally invasive approach. It is also the surgeon's responsibility to check the integrity of intraoperative instruments so as to minimize risks of complication and reassure the patient.


Assuntos
Cálculos Renais , Nefrolitotomia Percutânea , Nefrostomia Percutânea , Masculino , Humanos , Pessoa de Meia-Idade , Nefrolitotomia Percutânea/métodos , Nefrostomia Percutânea/métodos , Achados Incidentais , Cálculos Renais/diagnóstico por imagem , Cálculos Renais/cirurgia , Rim , Resultado do Tratamento
11.
Dalton Trans ; 52(19): 6239-6243, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37128862

RESUMO

We designed and synthesized a new tripyridine dipyrrolide pincer ligand, which could be doubly deprotonated to provide five-nitrogen-donor sites and then utilized to prepare a subnanometric chiral silver cluster. The cluster belongs to an S4 point group and shows a double-stranded helicate. DFT calculations were performed to analyze the electronic structure of the cluster. Interestingly, through hierarchical intercluster interactions, the cluster helicates evolve into complex secondary structures including a right-handed helix and a folded sheet, both of which are reminiscent of secondary structures of proteins, i.e., an α-helix and an antiparallel ß-sheet.

12.
Angew Chem Int Ed Engl ; 62(24): e202302595, 2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37052323

RESUMO

Conceptually mimicking biomolecules' ability to construct multiple-helical aggregates with emergent properties and functions remains a long-standing challenge. Here we report an atom-precise 18-copper nanocluster (NC), Cu18 H(PET)14 (TPP)6 (NCS)3 (Cu18 H) which contains a pseudo D3 -symmetrical triple-helical Cu15 core. Structurally, Cu18 H may be also viewed as sandwich type of sulfur-bridged chiral copper cluster units [Cu6 -Cu6 -Cu6 ], endowing three-layered 3D chirality. More importantly, the chiral NCs are aggregated into an infinite double-stranded helix supported by intra-strand homonuclear C-H⋅⋅⋅H-C dihydrogen contacts and inter-strand C-H/π and C-H/S interactions. The unique multi-layered 3D chirality and the double-helical assembly of Cu18 H are evocative of DNA. Moreover, the collective behaviours of the aggregated NCs not only exhibit crystallization-induced emission enhancement (CIEE) and aggregation-induced emission enhancement (AIEE) effects in the deep-red region, but also efficiently catalyze electron transfer (ET) reaction. This study thus presents that hierarchical assemblies of atomically defined copper NCs could be intricate as observed for important biomolecules like DNA with emergent properties arising from aggregated behaviours.

13.
BMC Cancer ; 23(1): 294, 2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37004022

RESUMO

BACKGROUND: Circulating tumor DNA (ctDNA) has been becoming a novel convenient and noninvasive method for dynamically monitoring landscape of genomic information to guild personalized cancer treatment. In this study we comprehensively evaluated the additional value of plasma ctDNA to routine tissue next generation sequencing (NGS) of therapeutically targetable mutations in lung cancers. METHODS: The tumor tissues and peripheral blood samples from 423 cases of patients with lung cancer were subjected to NGS of mutations in oncodrivers (EGFR, ERBB2, ALK, ROS1, C-MET, KRAS, BRAF, RET, BRCA1 and BRCA2). RESULTS: One hundred and ninety-seven cases showed both plasma and tissue positive and 96 showed both negative. The concordance for tissue and blood detection was 69.27% (293/423). 83 (19.62%) cases showed positive by tissue NGS alone and 47 (11.11%) positive by plasma ctDNA alone. The sensitivity of tissue and plasma detection was 85.63%, and 74.62%, respectively. Plasma had lower detection and sensitivity than tissue, but plasma additionally detected some important mutations which were omitted by tissue NGS. Plasma plus tissue increased the detection rate of 66.19% by tissue alone to 77.30% as well as the sensitivity of 85.63-100%. Similar results were also observed when the cases were classified into subpopulations according to different stages (IV vs. III vs. I-II), grades (low vs. middle grade) and metastatic status (metastasis vs. no metastasis). CONCLUSION: Plasma ctDNA shares a high concordance with tissue NGS, and plasma plus tissue enhances the detection rate and sensitivity by tissue alone, implying that the tissue and plasma detection should be mutually complementary in the clinical application.


Assuntos
DNA Tumoral Circulante , Neoplasias Pulmonares , Humanos , DNA Tumoral Circulante/genética , Biomarcadores Tumorais/genética , Proteínas Proto-Oncogênicas/genética , Neoplasias Pulmonares/patologia , Mutação , Sequenciamento de Nucleotídeos em Larga Escala/métodos
14.
Am J Case Rep ; 23: e937961, 2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-36403085

RESUMO

BACKGROUND Encrustation of the ureteral stent is a common complication that occurs after a prolonged indwelling duration. Other identified risk factors in the literature include urinary sepsis, chemotherapy, chronic renal failure, metabolic or congenital abnormalities, and nephrolithiasis. This report presents the case of a 39-year-old man with nephrolithiasis and fragmentation of a calcified right ureteric stent that required ureteroscopy and laser lithotripsy. CASE REPORT A 39-year-old man was initially admitted for ureteroscopy and laser lithotripsy after the diagnosis of bilateral urolithiasis. Ureteral stents were placed. One postoperative month later, the patient returned for follow-up and stent withdrawal. Follow-up computed tomography revealed a normal left kidney, intact bilateral ureteral stents, and residual right renal stones. However, an attempt to completely withdraw the stent failed and the patient had to undergo a secondary right ureteroscopy with laser lithotripsy. The fragmented proximal section of a calcified right ureteral stent with occluded lumen was found intraoperatively and sent for product analyses. After successful reintervention, the patient had a new right ureteral stent placed, which was successfully withdrawn during his next follow-up. CONCLUSIONS Ureteral stent encrustation may occur earlier than anticipated, possibly due to underlying patient risk factors. Complications, such as fragmentation of the ureteral stent, may occur during withdrawal. Physicians should be aware of any predictors for early ureteral stent encrustation to prevent unnecessary reintervention.


Assuntos
Cálculos Renais , Litotripsia a Laser , Ureter , Masculino , Humanos , Adulto , Ureteroscopia/métodos , Stents/efeitos adversos , Cálculos Renais/cirurgia
15.
Mol Med Rep ; 26(2)2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35795985

RESUMO

DEP domain containing 1 (DEPDC1) and forkhead box transcription factor 3a (FOXO3a) serve a role in tumor cells. To the best of our knowledge, however, the expression of DEPDC1 and FOXO3a in nephroblastoma and their role and potential mechanisms in nephroblastoma cells have not been reported. The aim of the present study was to characterize the expression of DEPDC1 and FOXO3a in nephroblastoma, as well as the underlying mechanisms. The expression levels of DEPDC1 and FOXO3a were detected using reverse transcription­quantitative PCR and western blotting. Cell viability, proliferation, invasion and migration were detected using Cell Counting Kit­8, colony formation, Transwell and wound healing assays, respectively. The activity of DEPDC1 promoter was detected by dual­luciferase reporter assay and the association between FOXO3a and DEPDC1 was detected using immunoprecipitation. DEPDC1 expression was significantly increased in nephroblastoma cells, particularly WiT49 cells. Compared with the negative control, DEPDC1 knockdown significantly inhibited proliferation, invasion and migration of WiT49 cells, while DEPDC1 overexpression (Ov) reversed these effects. By contrast, expression of FOXO3a was decreased in WiT49 cells and immunoprecipitation showed that FOXO3a bound to the DEPDC1 promoter. Ov­FOXO3a inhibited WiT49 cell proliferation, invasion and migration, as well as protein expression levels of phosphorylated­glycogen synthase kinase­3ß, Wnt3a and ß­catenin, while DEPDC1 Ov reversed the inhibitory effects of FOXO3a Ov on WiT49 cells. In conclusion, DEPDC1 promoted malignant progression of nephroblastoma via the Wnt/ß­catenin signaling pathway; this may be regulated by FOXO3a.


Assuntos
Proteína Forkhead Box O3 , Proteínas Ativadoras de GTPase , Proteínas de Neoplasias , Tumor de Wilms , Via de Sinalização Wnt , Proliferação de Células/fisiologia , Proteína Forkhead Box O3/genética , Proteína Forkhead Box O3/metabolismo , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Tumor de Wilms/genética , Tumor de Wilms/metabolismo
16.
Chem Commun (Camb) ; 58(10): 1577-1580, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35014990

RESUMO

Bimetallic cluster ion pairs containing a quaternary phosphonium and an ultrasmall Cu2Ag3 anionic cluster protected by thiolates: (PPh3R'')[Cu2Ag3(SR')6] (R'SH = cyclohexylthiol (CySH), R'' = Ph, 1; Me, 2; Et, 3; Pr, 4; R'SH = tert-butylthiol (tBuSH) and R'' = Ph, 5) were reported. Without any chiral source, 1 crystallizes as conglomerate crystals with homochiral packings and spontaneous resolution occurs, while four other clusters 2-5 crystallize as racemic crystals with heterochiral packings. These results indicate that racemic and homochiral crystallization in the cluster system could be controlled through fine-tuning internal achiral structural components.

17.
Inorg Chem ; 61(2): 1041-1050, 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-34965110

RESUMO

The nonahydridorhenate dianion ReH92- is a unique rhenium polyhydride complex due to its remarkably high coordination number; however, its detailed polytopal rearrangement process in either solution or crystal is so far unclear. In this work, our quantum chemical calculations have identified two previously unreported fluxional mechanisms for the ReH92- dianion in the K2ReH9 crystal: three-arm turnstile rotation and circle dance mechanism. These two polytopal rearrangements in the crystal offer an alternative interpretation to the pulse and wide-line NMR spectra (Farrar et al. J. Chem. Phys. 1969, 51, 3595). The previously postulated hindered rotation of the whole ReH92- dianion in K2ReH9 (White et al. J. Chem. Soc., Faraday Trans. 2 1972, 68, 1414) turns out to be a combination of the above-mentioned two elementary fluxional processes. In addition, our calculations have confirmed the Muetterties' D3h⇌C4v rearrangement as the intramolecular motion for the ReH92- dianion in solution.

18.
Nanoscale ; 13(46): 19642-19649, 2021 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-34816855

RESUMO

Cu is well-known to adopt a face-centered cubic (fcc) structure in the bulk phase. Ligand-stabilized Cu nanoclusters (NCs) with atomically precise structures are an emerging class of nanomaterials. However, it remains a great challenge to have non-fcc structured Cu NCs. In this contribution, we report the syntheses and total structure determination of six 28-nuclearity polyhydrido Cu NCs: [Cu28H16(dppp)4(RS)4(CF3CO2)8] (dppp = 1,3-bis(diphenylphosphino)propane, RSH = cyclohexylthiol, 1; tert-butylthiol, 3; and 2-thiophenethiol, 4) and [Cu28H16(dppe)4(RS)4(CH3CO2)6Cl2] (dppe = 1,2-bis(diphenylphosphino)ethane, RSH = (4-isopropyl)thiophenol, 2; 4-tert-butylbenzenethiol, 5; and 4-tert-butylbenzylmercaptan, 6). Their well-defined structures solved by X-ray single crystal diffraction reveal that these 28-Cu NCs are isostructural, and the overall metal framework is arranged as a sandwich structure with a core-shell Cu2@Cu16 unit held by two Cu5 fragments. One significant finding is that the organization of 18 Cu atoms in the Cu2@Cu16 could be regarded as an incomplete and distorted version of 3 × 2 × 2 "cutout" of the body-centered cubic (bcc) bulk phase, which was strikingly different to the fcc structure of bulk Cu. The bcc framework came as a surprise, as no bcc structures have been previously observed in Cu NCs. A comparison with the ideal bcc arrangement of 18 Cu atoms in the bcc lattice suggests that the distortion of the bcc structure results from the insertion of interstitial hydrides. The existence, number, and location of hydrides in these polyhydrido Cu NCs are established by combined experimental and DFT results. These results have significant implications for the development of high-nuclearity Cu hydride NCs with a non-fcc architecture.

19.
Inorg Chem ; 60(4): 2492-2502, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33533255

RESUMO

Hydride ligands of transition metal polyhydride complexes with a high coordination number are prone to fluxionality leading to interesting structural dynamics. However, the underlying polytopal rearrangement pathways have been rarely studied. Based on quantum chemical calculations carried out in this work with density functional theory and coupled-cluster theory, two new fluxional mechanisms have been identified for the rhenium polyhydride complex ReH5(PPh3)2(pyridine) to jointly account for two consecutive coalescence events in the variable-temperature NMR spectra upon heating: lateral and basal three-arm turnstile rotation. The frequently cited pseudorotation in ReH5(PPh3)2(pyridine) (Lee et al. Inorg. Chem. 1996, 35, 695) turns out to be a three-step process including two lateral three-arm turnstile steps and one basal turnstile step in between. The new fluxional mechanisms discovered in this work may also exist in other transition metal polyhydrides.

20.
Int J Chron Obstruct Pulmon Dis ; 15: 1997-2004, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32921997

RESUMO

Background: Chronic obstructive pulmonary disease (COPD) is a chronic airway inflammatory disease characterized by irreversible airflow obstruction. Pathogenic mechanisms underlying COPD remain largely unknown. Objective: The current study was designed to explore serum concentration of hypoxia-inducible factor 1α (HIF-1α) in stable COPD patients and the potential effect of Lycium barbarum polysaccharides (LBP) on HIF-1α protein expression. Methods: Serum HIF-1α was quantified by ELISA in 102 stable COPD patients before and after 2-week orally taken LBP (100 mL/time, twice daily, 5-15 mg/mL). Correlation of serum LBP and lung function (FEV1%) or blood gas (PO2 and PCO2) was also analyzed. As a control, 105 healthy subjects were also enrolled into this study. Results: Serum concentration of HIF-1α was significantly higher in the stable COPD patients (37.34 ± 7.20 pg/mL) than that in the healthy subjects (29.55 ± 9.66 pg/mL, P<0.001). Oral administration of LBP (5 mg/mL, 100 mL, twice daily for 2 weeks) not only relieved COPD symptoms but also significantly reduced serum HIF-1α concentration (36.94 ± 9.23 vs 30.49 ± 6.42 pg/mL, P<0.05). In addition, level of serum HIF-1α concentration was significantly correlated with PCO2 (r = 0.283, P<0.001), but negatively and significantly correlated with PO2 (r = -0.490, P=0.005) or FEV1%(r = -0.420, P=0.018). Conclusion: These findings suggested that activation of HIF-1 signaling pathway may be involved in the pathophysiology of COPD and that stabilization of serum HIF-1α concentration by LBP might benefit the stable COPD patients.


Assuntos
Medicamentos de Ervas Chinesas , Doença Pulmonar Obstrutiva Crônica , Medicamentos de Ervas Chinesas/farmacologia , Humanos , Fator 1 Induzível por Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia , Pulmão , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico
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