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1.
J Korean Med Sci ; 38(29): e232, 2023 Jul 24.
Article in English | MEDLINE | ID: mdl-37489719

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) is often a mild disease, usually manifesting with respiratory complaints, and is sometimes mortal due to multiple organ failure. Hyperinflammation is a known COVID-19 component and is associated with organ dysfunction, disease severity and mortality. Controlling hyperinflammatory response is crucial in determining treatment direction. An important agent in providing this control is corticosteroids. This study aimed to determine whether dexamethasone and methylprednisolone, doses, administration time and duration in COVID-19 treatment are associated with improved treatment outcomes. METHODS: This retrospective multicenter study was conducted with participation of 6 healthcare centers which collected data by retrospectively examining files of 1,340 patients admitted to intensive care unit due to COVID-19 between March 2020 and September 2021, diagnosed with polymerase chain reaction (+) and/or clinically and radiologically. RESULTS: Mortality in the pulse methylprednisolone group was statistically significantly higher than that in the other 3 groups. Mortality was higher in older patients with comorbidities such as hypertension, diabetes mellitus, chronic kidney failure, coronary artery disease, and dementia. Pulse and mini-pulse steroid doses were less effective than standard methylprednisolone and dexamethasone doses, pulse steroid doses being associated with high mortality. Standard-dose methylprednisolone and dexamethasone led to similar effects, but standard dose methylprednisolone was more effective in severe patients who required mechanical ventilation (MV). Infection development was related to steroid treatment duration, not cumulative steroid dose. CONCLUSION: Corticosteroids are shown to be beneficial in critical COVID-19, but the role of early corticosteroids in mild COVID-19 patients remains unclear. The anti-inflammatory effects of corticosteroids may have a positive effect by reducing mortality in severe COVID-19 patients. Although dexamethasone was first used for this purpose, methylprednisolone was found to be as effective at standard doses. Methylprednisolone administered at standard doses was associated with greater PaO2/FiO2 ratios than dexamethasone, especially in the severe group requiring MV. High dose pulse steroid doses are closely associated with mortality and standard methylprednisolone dose is recommended.


Subject(s)
COVID-19 , Methylprednisolone , Humans , Aged , Retrospective Studies , COVID-19 Drug Treatment , Critical Care , Dexamethasone
3.
North Clin Istanb ; 9(2): 131-139, 2022.
Article in English | MEDLINE | ID: mdl-35582516

ABSTRACT

Objective: Cytokine storm in coronavirus disease 2019 (COVID-19) patients causes lung damage and acute respiratory distress syndrome (ARDS). Immunomodulators such as steroids are widely used to control this situation. This study investigates the effectiveness of steroids used in COVID-19 patients, and their effects on secondary infections, morbidity, and mortality. Methods: Data were obtained by retrospectively scanning the files of patients in our hospital's intensive care unit clinic during the three peak periods. Results: Between the steroid and non-steroid groups, there was no statistically significant difference in reproductive rates. These rates were 49.7% and 43.2%, respectively. Reproductive rates among steroid types were determined as 25 (56.8%) in the Methylprednisolone group, 18 (69.2%) (Highest) in the Dexamethasone + Methylprednisolone group, and 54 (43.2%) (Lowest) in the Dexamethasone group. Steroid treatment duration was effective on reproduction. Steroids cause more infections, especially after invasive procedures (Tracheal intubation, central venous catheter, etc.). In the groups with and without tracheal aspirate steroids, the growth rates were 71 (76.3%) and 32 (54.2%) respectively. There was no difference in mortality between the groups. Conclusion: Cytokine storm causes lung damage and ARDS. Steroids can be useful in controlling this hyper-inflammatory situation. However, increased secondary infections, an important side effect of steroids, increase mortality. Steroids more often cause these infections, especially in patients undergoing invasive Strict adherence to infection control measures during steroid treatment will reduce this risk. In conclusion, while steroids reduce mortality by controlling the hyper-inflammatory picture, they also increase mortality with increased secondary infections. Preventing infections enables success with steroids.

4.
ChemSusChem ; 14(1): 398-407, 2021 Jan 07.
Article in English | MEDLINE | ID: mdl-33124721

ABSTRACT

This work introduces the facile and scalable two-step synthesis of Ti2 Nb10 O29 (TNO)/carbon hybrid material as a promising anode for lithium-ion batteries (LIBs). The first step consisted of a mechanically induced self-sustaining reaction via ball-milling at room temperature to produce titanium niobium carbide with a Ti and Nb stoichiometric ratio of 1 to 5. The second step involved the oxidation of as-synthesized titanium niobium carbide to produce TNO. Synthetic air yielded fully oxidized TNO, while annealing in CO2 resulted in TNO/carbon hybrids. The electrochemical performance for the hybrid and non-hybrid electrodes was surveyed in a narrow potential window (1.0-2.5 V vs. Li/Li+ ) and a large potential window (0.05-2.5 V vs. Li/Li+ ). The best hybrid material displayed a specific capacity of 350 mAh g-1 at a rate of 0.01 A g-1 (144 mAh g-1 at 1 A g-1 ) in the large potential window regime. The electrochemical performance of hybrid materials was superior compared to non-hybrid materials for operation within the large potential window. Due to the advantage of carbon in hybrid material, the rate handling was faster than that of the non-hybrid one. The hybrid materials displayed robust cycling stability and maintained ca. 70 % of their initial capacities after 500 cycles. In contrast, only ca. 26 % of the initial capacity was maintained after the first 40 cycles for non-hybrid materials. We also applied our hybrid material as an anode in a full-cell lithium-ion battery by coupling it with commercial LiMn2 O4 .

5.
Chem Commun (Camb) ; 56(75): 11082-11085, 2020 Sep 25.
Article in English | MEDLINE | ID: mdl-32812543

ABSTRACT

MAX phases are etched using an ionic liquid-water mixture to produce titanium carbide MXenes. The process avoids the use of any acid. Hydrolysis of the fluorine-containing ionic liquid leads to the selective removal of Al, while the ionic liquid is intercalated in-between the transition metal carbide layers.

6.
ChemSusChem ; 11(19): 3460-3472, 2018 Oct 11.
Article in English | MEDLINE | ID: mdl-30066492

ABSTRACT

Faradaic deionization is a promising new seawater desalination technology with low energy consumption. One drawback is the low water production rate as a result of the limited kinetics of the ion intercalation and insertion processes. We introduce the redox activities of iodide confined in carbon nanopores for electrochemical desalination. A fast desalination process was enabled by diffusionless redox kinetics governed by thin-layer electrochemistry. A cell was designed with an activated carbon cloth electrode in NaI aqueous solution, which was separated from the feedwater channel by a cation-exchange membrane. Coupled with an activated carbon counter electrode and an anion-exchange membrane, the half-cell in NaI with a cation-exchange membrane maintained performance even at a high current of 2.5 A g-1 (21 mA cm-2 ). The redox activities of iodide allowed a high desalination capacity of 69 mg g-1 (normalized by the mass of the working electrode) with stable performance over 120 cycles. Additionally, we provide a new analytical method for unique performance evaluation under single-pass flow conditions regarding the water production rate and energy consumption. Our cell concept provides flexible performance for low and high salinity and, thus, enables the desalination of brackish water or seawater. Particularly, we found a low energy consumption (1.63 Wh L-1 ) for seawater desalination and a high water production rate (25 L m-2 h-1 ) for brackish water.

7.
ChemSusChem ; 11(13): 2091-2100, 2018 Jul 11.
Article in English | MEDLINE | ID: mdl-29714401

ABSTRACT

The selective removal of ions by an electrochemical process is a promising approach to enable various water-treatment applications such as water softening or heavy-metal removal. Ion intercalation materials have been investigated for their intrinsic ability to prefer one specific ion over others, showing a preference for (small) monovalent ions over multivalent species. In this work, we present a fundamentally different approach: tunable ion selectivity not by modifying the electrode material, but by changing the operational voltage. We used titanium disulfide, which shows distinctly different potentials for the intercalation of different cations and formed binder-free composite electrodes with carbon nanotubes. Capitalizing on this potential difference, we demonstrated controllable cation selectivity by online monitoring the effluent stream during electrochemical operation by inductively coupled plasma optical emission spectrometry of aqueous 50 mm CsCl and MgCl2 . We obtained a molar selectivity of Mg2+ over Cs+ of 31 (strong Mg preference) in the potential range between -396 mV and -220 mV versus Ag/AgCl. By adjusting the operational potential window from -219 mV to +26 mV versus Ag/AgCl, Cs+ was preferred over Mg2+ by 1.7 times (Cs preference).

8.
ChemSusChem ; 11(13): 2101-2113, 2018 Jul 11.
Article in English | MEDLINE | ID: mdl-29710382

ABSTRACT

Lignin-derived carbon is introduced as a promising electrode material for water desalination by using capacitive deionization (CDI). Lignin is a low-cost precursor that is obtained from the cellulose and ethanol industries, and we used carbonization and subsequent KOH activation to obtain highly porous carbon. CDI cells with a pair of lignin-derived carbon electrodes presented an initially high salt adsorption capacity but rapidly lost their beneficial desalination performance. To capitalize on the high porosity of lignin-derived carbon and to stabilize the CDI performance, we then used asymmetric electrode configurations. By using electrodes of the same material but with different thicknesses, the desalination performance was stabilized through reduction of the potential at the positive electrode. To enhance the desalination capacity further, we used cell configurations with different materials for the positive and negative electrodes. The best performance was achieved by a cell with lignin-derived carbon as a negative electrode and commercial activated carbon as a positive electrode. Thereby, a maximum desalination capacity of 18.5 mg g-1 was obtained with charge efficiency over 80 % and excellent performance retention over 100 cycles. The improvements were related to the difference in the potential of zero charge between the electrodes. Our work shows that an asymmetric cell configuration is a powerful tool to adapt otherwise inappropriate CDI electrode materials.

9.
Urol J ; 15(4): 209-213, 2018 07 10.
Article in English | MEDLINE | ID: mdl-29464680

ABSTRACT

PURPOSE: The aim of this study is to compare the results of transurethral incision of the prostate (TUIP) and transurethral resection of the prostate (TURP) for the surgical treatment of benign prostate hyperplasia (BPH) in patients with renal transplantation. MATERIALS AND METHODS: Between April 2009 and May 2016, BPH patients with renal transplants whose prostate volumes were less than 30 cm3 were treated surgically. Forty-seven patients received TURP and 32 received TUIP. The patients' age, duration of dialysis, duration between transplant and TURP/TUIP, preoperative and postoperative serum creatinine (SCr), International Prostate Symptom Score (IPSS), maximum flow rate (Qmax) and postvoidresidual volume (PVR) were recorded. At 1-,6- and 12-month follow-up, early and long-term complications were assessed. Results were evaluated retrospectively. RESULTS: In both groups, SCr, PVR and IPSS decreased significantly after the operation, while Qmax increased significantly (P < .001). There was no difference between the two groups in terms of increase in Qmax and decrease in IPSS, SCr and PVR (P = .89, P = .27, P = .08, and P = .27). Among postoperative complications, urinary tract infection (UTIs) and retrograde ejaculation (RE) rates were higher in the TURP group than the TUIP group (12.7% versus 6.2% and 68.1% versus 25%,respectively), whereas urethral strictures were more prevalent in the TUIP group (12.5% versus 6.3%). CONCLUSION: For the treatment of BPH in renal transplant patients with a prostate volume less than 30 cm3, bothTUIP and TURP are safe and effective.


Subject(s)
Kidney Transplantation , Prostatic Hyperplasia/pathology , Prostatic Hyperplasia/surgery , Prostatism/physiopathology , Transurethral Resection of Prostate , Adult , Aged , Creatinine/blood , Follow-Up Studies , Humans , Male , Middle Aged , Organ Size , Prostatic Hyperplasia/complications , Prostatism/etiology , Retrospective Studies , Severity of Illness Index , Transurethral Resection of Prostate/adverse effects , Urethral Stricture/etiology , Urinary Tract Infections/etiology , Urodynamics
10.
ChemSusChem ; 10(24): 4914-4920, 2017 12 22.
Article in English | MEDLINE | ID: mdl-28685992

ABSTRACT

We present a novel multichannel membrane flow-stream capacitive deionization (MC-MCDI) concept with two flow streams to control the environment around the electrodes and a middle channel for water desalination. The introduction of side channels to our new cell design allows operation in a highly saline environment, while the feed water stream in the middle channel (conventional CDI channel) is separated from the electrodes with anion- and cation-exchange membranes. At a high salinity gradient between side (1000 mm) and middle (5 mm) channels, MC-MCDI exhibited an unprecedented salt-adsorption capacity (SAC) of 56 mg g-1 in the middle channel with charge efficiency close to unity and low energy consumption. This excellent performance corresponds to a fourfold increase in desalination performance compared to the state-of-the-art in a conventional CDI cell. The enhancement originates from the enhanced specific capacitance in high-molar saline media in agreement with the Gouy-Chapman-Stern theory and from a double-ion desorption/adsorption process of MC-MCDI through voltage operation from -1.2 to +1.2 V.


Subject(s)
Carbon/chemistry , Electrodes , Salinity , Adsorption , Membranes, Artificial , Sodium Chloride/chemistry , Sodium Chloride/isolation & purification
11.
ChemSusChem ; 8(11): 1823, 2015 Jun 08.
Article in English | MEDLINE | ID: mdl-26039519

ABSTRACT

Invited for this month's cover are the groups of Tim-Patrick Fellinger (MPI Potsdam) and Volker Presser (INM Saarbrücken and Saarland University). The image shows the dynamic process of ion electrosorption: anions are attracted and cations repelled from electrically charged electrodes based on carbons with heteroatoms. This process of capacitive deionization is particularly attractive for facile low-energy water treatment applications.


Subject(s)
Biomass , Carbon/chemistry , Electric Capacitance , Salts/chemistry
12.
ChemSusChem ; 8(11): 1867-74, 2015 Jun 08.
Article in English | MEDLINE | ID: mdl-25970654

ABSTRACT

Microporous carbons are an interesting material for electrochemical applications. In this study, we evaluate several such carbons without/with N or S doping with regard to capacitive deionization. For this purpose, we extent the salt-templating synthesis towards biomass precursors and S-doped microporous carbons. The sample with the largest specific surface area (2830 m(2) g(-1) ) showed 1.0 wt % N and exhibited a high salt-sorption capacity of 15.0 mg g(-1) at 1.2 V in 5 mM aqueous NaCl. While being a promising material from an equilibrium performance point of view, our study also gives first insights to practical limitations of heteroatom-doped carbon materials. We show that high heteroatom content may be associated with a low charge efficiency. The latter is a key parameter for capacitive deionization and is defined as the ratio between the amounts of removed salt molecules and electrical charge.


Subject(s)
Biomass , Carbon/chemistry , Electric Capacitance , Sodium Chloride/chemistry , Polymerization , Porosity , Salinity
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