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1.
J Neurosurg Case Lessons ; 7(13)2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38531080

ABSTRACT

BACKGROUND: Isolated cerebral mucormycosis is rare in immunocompetent adults and is only sparsely reported to be associated with obstructive hydrocephalus. OBSERVATIONS: Here, the authors report a case of obstructive hydrocephalus secondary to central nervous system mucormycosis without other systems or rhino-orbital involvement and its technical surgical management. A 23-year-old, incarcerated, immunocompetent patient with history of intravenous (IV) drug use presented with syncope. Although clinical and radiographic findings failed to elucidate an infectious pathology, endoscopy revealed an obstructive mass lesion at the level of the third ventricle, which, on microbiological testing, was confirmed to be Rhizopus fungal ventriculitis. Perioperative cerebrospinal fluid diversion, endoscopic third ventriculostomy, endoscopic biopsy technique, patient outcomes, and the literature are reviewed here. The patient received intrathecal and IV amphotericin B followed by a course of oral antifungal treatment and currently remains in remission. LESSONS: The patient's unique presentation and diagnosis of isolated cerebral mucormycosis reveal this pathogen as a cause of ventriculitis and obstructive hydrocephalus in immunocompetent adult patients, even in the absence of infectious sequelae on neuroimaging.

2.
Article in English | MEDLINE | ID: mdl-38196127

ABSTRACT

AIMS: Catheter-based radiofrequency renal denervation (RF RDN) has recently been approved for clinical use in the European Society of Hypertension guidelines and by the US FDA. This study evaluated the lifetime cost-effectiveness of RF RDN using contemporary evidence. METHODS AND RESULTS: A decision-analytic model based on multivariate risk equations projected clinical events, quality-adjusted life years (QALYs) and costs. The model consisted of seven health states: hypertension alone, myocardial infarction (MI), other symptomatic coronary artery disease, stroke, heart failure (HF), end-stage renal disease, and death. Risk reduction associated with changes in office systolic blood pressure (oSBP) was estimated based on a published meta-regression of hypertension trials. The base case effect size of -4.9 mmHg oSBP (observed vs. sham control) was taken from the SPYRAL HTN-ON MED trial of 337 patients. Costs were based on NHS England data. The incremental cost-effectiveness ratio (ICER) was evaluated against the NICE cost-effectiveness threshold of £20 000-30 000 per QALY gained. Extensive scenario and sensitivity analyses were conducted, including the ON-MED subgroup on three medications and pooled effect sizes. RF RDN resulted in a relative risk reduction in clinical events over 10 years (0.80 for stroke, 0.88 for MI, 0.72 for HF), with an increase in health benefit over a patient's lifetime, adding 0.35 QALYs at a cost of £4 763, giving an ICER of £13 482 per QALY gained. Findings were robust across tested scenarios. CONCLUSION: Catheter-based radiofrequency RDN can be a cost-effective strategy for uncontrolled hypertension in the UK, with an ICER substantially below the NICE cost-effectiveness threshold. Funding: Medtronic Inc.

3.
Neurol Ther ; 12(6): 2133-2146, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37824047

ABSTRACT

INTRODUCTION: Tonic motor activation (TOMAC) therapy is a novel non-pharmacologic treatment approach for patients suffering from medication-refractory restless legs syndrome (RLS). The objective of this study was to explore the potential cost-effectiveness of TOMAC in the US healthcare system. METHODS: A decision-analytic Markov model was constructed to project strategy-specific treatment costs and benefits over 3 years and lifetime. Cohort characteristics (mean age 57.4 years, 39.8% male) and treatment effects were derived from the sham-controlled RESTFUL study. Study-observed International RLS Study Group (IRLS) scores were used to estimate changes in healthcare resource utilization and quality of life based on mapping algorithms informed by published data. The incremental cost-effectiveness ratio (ICER) was evaluated against established willingness-to-pay thresholds of $50,000/$150,000 per QALY to determine cost-effectiveness. Extensive scenario analyses were performed, including longer-term extension study data. RESULTS:  TOMAC and sham reduced IRLS scores from baseline 25.3 to 18.10 and 21.60, respectively, at 4 weeks (treatment effect - 3.4 vs. sham), with an increase in utility from 0.80 to 0.84 (0.75-0.84 vs. baseline). Over 3 years and lifetime, the TOMAC vs. sham effect size corresponded to an added 0.10 and 0.49 QALYs (2.36 vs. 2.26; 12.59 vs. 12.10) at incremental costs of $8061 and $36,373 ($36,707 vs. $28,646; $224,040 vs.$187,667), resulting in ICER estimates of $83,822 and $73,600, respectively. Compared to baseline, TOMAC resulted in ICER estimates of $29,569 and $23,690 over 3 years and lifetime, respectively. TOMAC remained cost-effective or dominant across all scenarios, with ICERs ranging from $10,530-$83,822 and - $8061 to $29,569 vs. sham and baseline, respectively. Larger TOMAC effect sizes, achieved per extension study data, further increased cost-effectiveness. CONCLUSION:  Based on this exploratory analysis of published trial data, TOMAC therapy appears to offer meaningful improvements in patient health-related quality at net costs that render it a cost-effective intervention. Further analyses are warranted.

4.
Surg Endosc ; 37(10): 7759-7766, 2023 10.
Article in English | MEDLINE | ID: mdl-37580581

ABSTRACT

BACKGROUND: Diverting ileostomy and colostomy after total mesorectal excision reduces the risk of complications related to anastomotic leakages but is associated with a reduction in health-related quality of life and long-term economic consequences that are unknown. Our objective was to estimate the lifetime costs of stoma placement after rectal cancer resection in the U.S., England, and Germany. METHODS: Input parameters were derived from quasi-systematic literature searches. Decision-analytic models with survival from colorectal cancer-adjusted life tables and country-specific stoma reversal proportions were created for the three countries to calculate lifetime costs. Main cost items were stoma maintenance costs and reimbursement for reversal procedures. Discounting was applied according to respective national guidelines. Sensitivity analysis was conducted to explore the impact of parameter uncertainty onto the results. RESULTS: The cohort starting ages and median survival were 63 and 11.5 years for the U.S., 69 years and 8.5 years for England, and 71 and 6.5 years for Germany. Lifetime discounted stoma-related costs were $26,311, £9512, and €10,021, respectively. All three models were most sensitive to the proportion of ostomy reversal, age at baseline, and discount rate applied. CONCLUSION: Conservative model-based projections suggest that stoma care leads to significant long-term costs. Efforts to reduce the number of patients who need to undergo a diverting ostomy could result in meaningful cost savings.


Subject(s)
Rectal Neoplasms , Surgical Stomas , Humans , Quality of Life , Rectal Neoplasms/surgery , Rectum/surgery , Ileostomy/methods , Colostomy/methods , Anastomosis, Surgical , Retrospective Studies , Postoperative Complications/etiology , Postoperative Complications/prevention & control
5.
Int J Technol Assess Health Care ; 39(1): e32, 2023 Jun 06.
Article in English | MEDLINE | ID: mdl-37277322

ABSTRACT

OBJECTIVES: To assess the potential cost-effectiveness of neuromuscular electrical stimulation (NMES) for treatment of mild obstructive sleep apnea (OSA). METHODS: A decision-analytic Markov model was developed to estimate health state progression, incremental cost, and quality-adjusted life year (QALY) gain of NMES compared to no treatment, continuous airway pressure (CPAP), or oral appliance (OA) treatment. The base case assumed no cardiovascular (CV) benefit for any of the interventions, while potential CV benefit was considered in scenario analyses. Therapy effectiveness was based on a recent multi-center trial for NMES, and on the TOMADO and MERGE studies for OA and CPAP. Costs, considered from a United States payer perspective, were projected over lifetime for a 48-year-old cohort, 68% of whom were male. An incremental cost-effectiveness ratio (ICER) threshold of USD150,000 per QALY gained was applied. RESULTS: From a baseline AHI of 10.2 events/hour, NMES, OA and CPAP reduced the AHI to 6.9, 7.0 and 1.4 events/hour respectively. Long-term therapy adherence was estimated at 65-75% for NMES and 55% for both OA and CPAP. Compared to no treatment, NMES added between 0.268 and 0.536 QALYs and between USD7,481 and USD17,445 in cost, resulting in ICERs between USD15,436 and USD57,844 per QALY gained. Depending on long-term adherence assumptions, either NMES or CPAP were found to be the preferred treatment option, with NMES becoming more attractive with younger age and assuming CPAP was not used for the full night in all patients. CONCLUSIONS: NMES might be a cost-effective treatment option for patients with mild OSA.


Subject(s)
Continuous Positive Airway Pressure , Sleep Apnea, Obstructive , Humans , Male , Middle Aged , Female , Cost-Benefit Analysis , Continuous Positive Airway Pressure/methods , Sleep Apnea, Obstructive/therapy , Health Services , Electric Stimulation
7.
Eur Heart J Qual Care Clin Outcomes ; 9(6): 575-582, 2023 09 12.
Article in English | MEDLINE | ID: mdl-36057838

ABSTRACT

AIMS: Renal denervation has been shown to lower blood pressure in sham-controlled trials and represents a device-based treatment option for hypertension. We sought to project clinical event reductions after radiofrequency renal denervation using a novel modelling approach. METHODS AND RESULTS: The Global SYMPLICITY Registry is a global, prospective all-comer registry to evaluate safety and efficacy after renal denervation. For this analysis, change in office systolic blood pressure from baseline was calculated from reported follow-up in the Global SYMPLICITY Registry. Relative risks for death and other cardiovascular events as well as numbers needed to treat for event avoidance were obtained for the respective blood pressure reductions based on previously reported meta-regression analyses for the full cohort and high-risk subgroups including type 2 diabetes, chronic kidney disease, resistant hypertension, and high basal cardiovascular risk. Average baseline office systolic blood pressure and reduction estimates for the full cohort (N = 2651) were 166±25 and -14.8 ± 0.4 mmHg, respectively. Mean reductions in blood pressure ranged from -11.0--21.8 mmHg for the studied high-risk subgroups. Projected relative risks ranged from 0.57 for stroke in the resistant hypertension cohort to 0.92 for death in the diabetes cohort. Significant absolute reductions in major adverse cardiovascular events over 3 years compared with the projected control (8.6 ± 0.7% observed vs. 11.7 ± 0.9% for projected control; P < 0.01) were primarily due to reduced stroke incidence. The robustness of findings was confirmed in sensitivity and scenario analyses. CONCLUSION: Model-based projections suggest radiofrequency renal denervation for patients with uncontrolled hypertension adds considerable clinical benefit across a spectrum of different cohort characteristics.


Subject(s)
Diabetes Mellitus, Type 2 , Hypertension , Stroke , Humans , Prospective Studies , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/epidemiology , Sympathectomy/methods , Treatment Outcome , Hypertension/epidemiology , Hypertension/surgery , Hypertension/drug therapy , Registries
8.
Angew Chem Int Ed Engl ; 61(49): e202214055, 2022 Dec 05.
Article in English | MEDLINE | ID: mdl-36224094

ABSTRACT

Photo-catalysis by small-molecules is often limited by catalyst degradation and low electron-transfer efficiency. Herein we report a stable N-phenyl-phenothiazine (PTH)-derived porous coordination cage (PCC) as a highly efficient photocatalyst. By the incorporation of the photocatalytic PTH moiety into a PCC, aggregation-induced quenching (AIQ) was shown to be reduced. An improvement in catalyst stability was discovered, ascribed to the synergistic effects of the PTH moieties. The catalyst, operating through a photolytic single-electron transfer, was utilized for photo-catalyzed dehalogenation and borylation. Evaluation of the catalytic mechanism in the borylation reaction showed that the improved performance results from the more efficient formation of the electron donor-acceptor (EDA) complex with the cage. This discovery provides a potential strategy to improve the photophysical properties and stabilities of small-molecule organic photocatalysts via supramolecular chemistry.

9.
Ann N Y Acad Sci ; 1518(1): 226-230, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36183322

ABSTRACT

Metal-organic frameworks (MOFs) are hybrid materials known for their nanoscale pores, which give them high surface areas but generally lead to poor electrical conductivity. Recently, MOFs with high electrical conductivity were established as promising materials for a variety of applications in energy storage and catalysis. Many recent reports investigating the fundamentals of charge transport in these materials focus on the role of the organic ligands. Less consideration, however, is given to the metal ion forming the MOF, which is almost exclusively a late first-row transition metal. Here, we report a moderately conductive porous MOF based on trivalent gallium and 2,3,6,7,10,11-hexahydroxytriphenylene. Gallium, a metal that has not been featured in electrically conductive MOFs so far, has a closed-shell electronic configuration and is present in its trivalent state-in contrast to most conductive MOFs, which are formed by open-shell, divalent transition metals. Our material, made without using any harmful solvents, displays conductivities on the level of 3 mS/cm and a surface area of 196 m2 /g, comparable to transition metal analogs.

10.
Nephrology (Carlton) ; 27(11): 859-868, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36068700

ABSTRACT

AIM: The recent IN.PACT AV Access study found drug-coated balloon therapy to be associated with reduced reinterventions compared to percutaneous transluminal angioplasty using standard balloons in the management of arteriovenous fistula stenosis. The economic implications of drug-coated balloon use in Asia, including Japan and Korea, remain unknown. METHODS: A decision-analytic model was developed to calculate strategy-specific costs for Korea and Japan through 5-year follow-up. The analysis assumed maintained therapy benefit beyond current trial follow-up of 1 year in the base case, with several alternative scenarios explored in sensitivity analysis. Costs were derived from claims and reimbursement data, and projections were evaluated at 3 and 5 years post-index procedure. RESULTS: Model-projected access circuit reintervention events for drug-coated versus standard balloons were 1.70 versus 2.76 (-1.06) and 2.53 versus 4.10 (-1.57) at 3 and 5 years in the base case. Corresponding 3- and 5-year costs were ₩6 211 103 versus ₩7 605 553 (-₩1 394 451) and ₩7 766 051 versus ₩10 124 954 (-₩2 358 904) in Korea, and ¥1 469 824 versus ¥1 504 161 (-¥34 337) and ¥1 956 931 versus ¥2 106 632 (-¥149 701) in Japan. In scenario analyses, drug-coated balloons remained cost saving at 3- and 5-year follow-up in Korea, but required up to 5 years to reach cost-savings in Japan. Drug-coated balloon use in reinterventions increased projected savings, as did younger treatment age. CONCLUSION: Treatment of arteriovenous fistulas with the IN.PACT AV drug-coated balloon, based on preliminary data, may lead to meaningful reductions in reintervention costs that would render it cost-saving at timeframes of around 1 year in Korea and between 3 and 5 years in Japan.


Subject(s)
Angioplasty, Balloon , Arteriovenous Fistula , Arteriovenous Shunt, Surgical , Cardiovascular Agents , Angioplasty, Balloon/methods , Coated Materials, Biocompatible , Constriction, Pathologic , Humans , Japan , Paclitaxel , Renal Dialysis/methods , Time Factors , Treatment Outcome , Vascular Patency
11.
Proc Natl Acad Sci U S A ; 119(34): e2205127119, 2022 Aug 23.
Article in English | MEDLINE | ID: mdl-35969747

ABSTRACT

Metallic charge transport and porosity appear almost mutually exclusive. Whereas metals demand large numbers of free carriers and must have minimal impurities and lattice vibrations to avoid charge scattering, the voids in porous materials limit the carrier concentration, provide ample space for impurities, and create more charge-scattering vibrations due to the size and flexibility of the lattice. No microporous material has been conclusively shown to behave as a metal. Here, we demonstrate that single crystals of the porous metal-organic framework Ln1.5(2,3,6,7,10,11-hexaoxytriphenylene) (Ln = La, Nd) are metallic. The materials display the highest room-temperature conductivities of all porous materials, reaching values above 1,000 S/cm. Single crystals of the compounds additionally show clear temperature-deactivated charge transport, a hallmark of a metallic material. Lastly, a structural transition consistent with charge density wave ordering, present only in metals and rare in any materials, provides additional conclusive proof of the metallic nature of the materials. Our results provide an example of a metal with porosity intrinsic to its structure. We anticipate that the combination of porosity and chemical tunability that these materials possess will provide a unique handle toward controlling the unconventional states that lie within them, such as charge density waves that we observed, or perhaps superconductivity.

12.
ACS Omega ; 6(44): 29567-29576, 2021 Nov 09.
Article in English | MEDLINE | ID: mdl-34778628

ABSTRACT

Extracellular histone H4 is an attractive drug target owing to its roles in organ failure in sepsis and other diseases. To identify inhibitors using in silico methods, information on histone H4 structural dynamics and three-dimensional (3D) structural coordinates is required. Here, DNA-free histone H4 type 1 (H4.1) was characterized by utilizing tandem nonlinear and linear ion mobility spectrometry (FAIMS-TIMS) coupled to mass spectrometry (MS) complemented with molecular dynamics (MD) simulations. The gas-phase structures of H4.1 are dependent on the starting solution conditions, evidenced by differences in charge state distributions, mobility distributions, and collision-induced unfolding (CIU) pathways. The experimental results show that H4.1 adopts diverse conformational types from compact (C) to partially folded (P) and subsequently elongated (E) structures. Molecular dynamics simulations provided candidate structures for the histone H4.1 monomer in solution and for the gas-phase structures observed using FAIMS-IMS-TOF MS as a function of the charge state and mobility distribution. A combination of the FAIMS-TIMS experimental results with theoretical dipole calculations reveals the important role of charge distribution in the dipole alignment of H4.1 elongated structures at high electric fields. A comparison of the secondary and primary structures of DNA-free H2A.1 and H4.1 is made based on the experimental IMS-MS and MD findings.

14.
J Phys Chem B ; 125(19): 4977-4986, 2021 05 20.
Article in English | MEDLINE | ID: mdl-33974801

ABSTRACT

Histones are highly basic chromatin proteins that tightly package and order eukaryotic DNA into nucleosomes. While the atomic structure of the nucleosomes has been determined, the three-dimensional structure of DNA-free histones remains unresolved. Here, we combine tandem nonlinear and linear ion mobility spectrometry (FAIMS-TIMS) coupled to mass spectrometry in parallel with molecular modeling to study the conformational space of a DNA-free histone H2A type 1 (H2A.1). Experimental results showed the dependence of the gas-phase structures on the starting solution conditions, characterized by charge state distributions, mobility distributions, and collision-induced-unfolding pathways. The measured H2A.1 gas-phase structures showed a high diversity of structural features ranging from compact (C) to partially folded (P) and then highly elongated (E) conformations. Molecular dynamics simulations provided candidate structures for the solution H2A.1 native conformation with folded N- and C-terminal tails, as well as gas-phase candidate structures associated with the mobility trends. Complementary collision cross section and dipole calculations showed that the charge distribution in the case of elongated gas-phase structures, where basic and acidic residues are mostly exposed (e.g., z > 15+), is sufficient to induce differences in the dipole alignment at high electric fields, in good agreement with the trends observed during the FAIMS-TIMS experiments.


Subject(s)
Histones , Nucleosomes , DNA , Histones/metabolism , Humans , Ion Mobility Spectrometry , Molecular Dynamics Simulation
15.
J Am Chem Soc ; 143(4): 1836-1845, 2021 02 03.
Article in English | MEDLINE | ID: mdl-33373218

ABSTRACT

Human indoleamine 2,3-dioxygenase 1 (hIDO1) and human tryptophan dioxygenase (hTDO) are two important heme proteins that degrade the essential amino acid, l-tryptophan (Trp), along the kynurenine pathway. The two enzymes share a similar active site structure and an analogous catalytic mechanism, but they exhibit a variety of distinct functional properties. Here we used carbon monoxide (CO) as a structural probe to interrogate how the functionalities of the two enzymes are encoded in their structures. With X-ray crystallography, we detected an unexpected photochemical intermediate trapped in a crystal of the hIDO1-CO-Trp complex, where CO is photolyzed from the heme iron by X-rays at cryogenic temperatures (100 K). The CO photolysis triggers a large-scale migration of the substrate Trp, as well as the photolyzed CO, from the active site to a temporary binding site, Sa*. It is accompanied by a large conformational change to an active site loop, JK-LoopC, despite the severely restricted protein motion under the frozen conditions, which highlights the remarkable conformational plasticity of the hIDO1 protein. Comparative studies of a crystal of the hTDO-CO-Trp complex show that CO and Trp remain bound in the active site under comparable X-ray illumination, indicating a much more rigid protein architecture. The data offer important new insights into the structure and function relationships of the heme-based dioxygenases and provide new guidelines for structure-based design of inhibitors targeting them.


Subject(s)
Dioxygenases/chemistry , Heme/chemistry , Catalytic Domain , Crystallography, X-Ray , Dioxygenases/antagonists & inhibitors , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Humans , Photochemical Processes , Protein Conformation , Structure-Activity Relationship , Substrate Specificity
16.
Eur J Oral Sci ; 129(1): e12749, 2021 02.
Article in English | MEDLINE | ID: mdl-33381873

ABSTRACT

This study investigated the potential of red wine in modulating dental erosion kinetics in the presence or absence of salivary pellicle. Polished human enamel specimens were used in two conditions; presence or absence of acquired enamel pellicle; and subdivided according to exposure: red wine, orange juice, apple juice, or citric acid. The specimens were incubated in clarified whole human saliva (presence of acquired enamel pellicle) or in a humid chamber (absence of acquired enamel pellicle) for 2 h at 37°C, then in the test substances for 1 min, at 25°C, under shaking. This was repeated four times. Surface hardness was measured initially and after each cycle and surface reflection intensity was measured initially and after all cycles. In the presence of acquired enamel pellicle, red wine caused the least surface hardness loss, followed by orange juice, apple juice, and citric acid. Statistically significantly less surface reflection intensity loss was observed for red wine and orange juice than for apple juice and citric acid. In the absence of acquired enamel pellicle, red wine and orange juice caused less surface hardness loss than apple juice and citric acid. Orange juice showed the least surface reflection intensity loss, followed by red wine, citric acid, and apple juice. The polyphenol composition of these drinks can notably modulate the erosion kinetics.


Subject(s)
Tooth Erosion , Wine , Dental Enamel , Dental Pellicle , Humans , Kinetics , Saliva
17.
Bioinformatics ; 36(19): 4910-4917, 2020 12 08.
Article in English | MEDLINE | ID: mdl-33141147

ABSTRACT

MOTIVATION: Recent neural approaches on event extraction from text mainly focus on flat events in general domain, while there are less attempts to detect nested and overlapping events. These existing systems are built on given entities and they depend on external syntactic tools. RESULTS: We propose an end-to-end neural nested event extraction model named DeepEventMine that extracts multiple overlapping directed acyclic graph structures from a raw sentence. On the top of the bidirectional encoder representations from transformers model, our model detects nested entities and triggers, roles, nested events and their modifications in an end-to-end manner without any syntactic tools. Our DeepEventMine model achieves the new state-of-the-art performance on seven biomedical nested event extraction tasks. Even when gold entities are unavailable, our model can detect events from raw text with promising performance. AVAILABILITY AND IMPLEMENTATION: Our codes and models to reproduce the results are available at: https://github.com/aistairc/DeepEventMine. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Subject(s)
Language , Research Design
18.
Waste Manag ; 118: 610-625, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33010692

ABSTRACT

China produced a large amount of construction and demolition (C&D) waste, owing to the rapid development of construction industry. Although a set of policies and regulations are being drafted in China for promoting C&D waste recycling, execution of these policies in practice seems to be far from effective. Currently, approximately 75% of Chinese cities are still surrounded by large volumes of C&D waste. Therefore, identification of challenges in the development of C&D waste management, specially recycling, is essential. This paper employs site visits to 10 recycling plants in 10 Chinese cities (Shanghai, Hangzhou, Suzhou, Chongqing, Chengdu, Xi'an, Changsha, Shenzhen, Nanjing, and Zhoukou) and interviews with 25 industry practitioners for examining the challenges. Eight challenges are identified: (1) unstable source of C&D waste for recycling, (2) absence of subsidies for recycling activities and high cost for land use, (3) insufficient attention paid to design for waste minimisation, (4) absence of regulations on on-site sorting, (5) unregulated landfill activities, (6) a lack of coordination among different government administration departments, (7) a lack of accurate estimation of waste quantity and distribution, and (8) a lack of an effective waste tracing system. Recommendations to address these challenges are presented. The results of this study are expected to aid policy makers in formulation of proper C&D waste management in China and provide a useful reference for researchers who are interested in C&D waste recycling industry.


Subject(s)
Construction Materials , Waste Management , China , Cities , Recycling
19.
Ann Card Anaesth ; 23(4): 447-452, 2020.
Article in English | MEDLINE | ID: mdl-33109802

ABSTRACT

Context: The concomitant use of cuffed endotracheal tubes (ETT) and transesophageal echocardiography (TEE) probes increases ETT cuff pressures (CP), which may contribute to mucosal ischemia and perioperative complications such as failed extubation. Aims: To assess changes in ETT CP after TEE insertion in patients of different age groups undergoing congenital heart surgery and examine the relationship between ETT CP and postoperative extubation failure. Settings and Design: Single-center quality improvement project. Subjects and Methods: ETT CP was measured with a manometer following intubation and again after TEE insertion. Tracheal perfusion pressure was then calculated and postoperative extubation failures were recorded. Statistical Analysis: Chi-square testing, Fisher's-exact testing, one-way analysis of variance testing or Kruskal-Wallis testing with Dunn's pairwise, and student's t-test or Wilcoxon rank-sum testing were used to analyze the data. Results: Median ETT CP increased significantly after TEE insertion in each age group, with infants showing a smaller magnitude of increase (+2 [1-6] cm H2O, P < 0.001) than adults (+12 [8-14] cm H2O, P = 0.008) (intergroup comparison P = 0.002). Five patients (9%) failed extubation, all of which were infants. Within the infant subgroup, no significant difference existed between failed vs successful extubation regarding ETT CP during bypass (15 ± 1 vs 16 ± 2 mmHg, P = 0.206) or tracheal perfusion pressure pre-bypass (34 ± 9 vs 38 ± 11 mmHg, P = 0.518), during bypass (20 ± 9 vs 22 ± 6 mmHg, P = 0.697), or post-bypass (42 ± 9 vs 41 ± 9 mmHg, P = 0.923). There was a significant difference in cardiopulmonary bypass duration (151 ± 29 vs 85 ± 32 min, P < 0.001). Conclusion: Factors beyond intraoperative ETT CP likely play a larger role in postoperative extubation failure.


Subject(s)
Airway Extubation , Cardiac Surgical Procedures , Intubation, Intratracheal , Adolescent , Adult , Cardiopulmonary Bypass , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Trachea/diagnostic imaging
20.
J Am Chem Soc ; 142(45): 19291-19299, 2020 11 11.
Article in English | MEDLINE | ID: mdl-33119281

ABSTRACT

Through comprehensive analysis of carboxylate-based metal-organic frameworks (MOFs), we present general evidence that challenges the common perception of MOF metal-linker bonds being static. Structural dynamics in MOFs, however, typically refers to the "breathing" behavior of cavities, where pores open and close in response to guest molecules, and to the transient binding of guest molecules, but dynamic bonding would explain important MOF phenomena in catalysis, postsynthetic exchange, negative thermal expansion, and crystal growth. Here, we demonstrate, through use of variable-temperature diffuse reflectance infrared Fourier transform spectroscopy (VT-DRIFTS) aided by ab initio plane wave density functional theory, that similar evidence for melting behavior in zeolitic imidazolate frameworks (ZIFs), i.e., reversible metal-linker bonding, driven by specific vibrational modes, can be observed for carboxylate MOFs by monitoring the red-shifts of carboxylate stretches coupled to anharmonic metal-carboxylate oscillators. To demonstrate the generality of these findings, we investigate a wide class of carboxylate MOFs that includes iconic examples with diverse structures and metal-linker chemistry. As the very vibrations invoked in ZIF melting but heretofore unobserved for carboxylate MOFs, these metal-linker dynamics resemble the ubiquitous soft modes that trigger important phase transitions in diverse classes of materials while offering a fundamentally new perspective for the design of next-generation metal-organic materials.

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