Solvothermal synthesis of high-performance Ni-Co layered double hydroxide nanofoam electrode for electrochemical energy storage

Patel, R.,Inamdar, A.I.,Hou, B.,Cha, S.,Ansari, A.T.,Gunjakar, J.L.,Im, H.,Kim, H. ELSEVIER 2017 CURRENT APPLIED PHYSICS Vol.17 No.4

<P>A nanofoam nickel cobalt layered double hydroxide (NiCo(OH)(2)) electrode film is fabricated on a stainless-steel substrate with the use of a simple one-step solvothermal process. The nanofoam NiCo(OH)(2) electrode exhibits a high specific capacitance of 2710.2 Fig at a current density.of 9.1 A/g, and a good capacity retention of similar to 70% after 2000 charge-discharge cycles at a high current density of 31.8 A/g. An energy density of 60.23 Wh/kg is obtained at a power density of 1.8 kW/kg. The excellent electrochemical energy storage performance of the NiCo(OH)(2) electrode is due to the synergetic effect of a significantly improved ionic diffusion and an effective charge transfer, which is linked to a well-dispersed interconnected nanofoam morphology and binder-free direct contact with the current collector. (C) 2017 Elsevier B.V. All rights reserved.</P>

Discovery of a New Nucleoside Template for Human A₃ Adenosine Receptor Ligands : D-4'-Thioadenosine Derivatives without 4'-Hydroxymethyl Group as Highly Potent and Selective Antagonists

Jeong, Lak Shin,Choe, Seung Ah,Gunaga, Prashantha,Kim, Hea Ok,Lee, Hyuk Woo,Lee, Sang Kook,Tosh, Dilip K.,Patel, Amit,Palaniappan, Krishnan K.,Gao, Zhan-Guo,Jacobson, Kenneth A.,Moon, Hyung Ryong 이화여자대학교 약학연구소 2008 藥學硏究論文集 Vol.- No.18

Truncated D-4'-thioadenosine derivatives lacking the 4'-hydroxymethylene moiety were synthesized starting from D-mannose, using cyclization to the 4-thiosugar and one-step conversion of the diol to the acetate as key steps At the human A₃ adenosine receptor (AR), N^(6)-substituted purine analogues bound potently and selectively and acted as antagonists in a cyclic AMP functional assay An N^(6)-(3-chlorobenzyl)purine analogue 9b displayed a K, value of 1 66 nM at the human A₃ AR Thus, truncated D-4'-thioadenosine is an excellent template for Ihe design of novel A₃ AR antagonists to act at both human and murine species.

Selective removal of heavy metal ions by disulfide linked polymer networks

Ko, Dongah,Lee, Joo Sung,Patel, Hasmukh A.,Jakobsen, Mogens H.,Hwang, Yuhoon,Yavuz, Cafer T.,Hansen, Hans Chr. Bruun,Andersen, Henrik R. Elsevier 2017 Journal of hazardous materials Vol.332 No.-

<P><B>Abstract</B></P> <P>Heavy metal contaminated surface water is one of the oldest pollution problems, which is critical to ecosystems and human health. We devised disulfide linked polymer networks and employed as a sorbent for removing heavy metal ions from contaminated water. Although the polymer network material has a moderate surface area, it demonstrated cadmium removal efficiency equivalent to highly porous activated carbon while it showed 16 times faster sorption kinetics compared to activated carbon, owing to the high affinity of cadmium towards disulfide and thiol functionality in the polymer network. The metal sorption mechanism on polymer network was studied by sorption kinetics, effect of pH, and metal complexation. We observed that the metal ions–copper, cadmium, and zinc showed high binding affinity in polymer network, even in the presence of competing cations like calcium in water.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Disulfide/thiol polymer networks are promising as sorbent for heavy metals. </LI> <LI> Rapid sorption and high Langmuir affinity constant (a<SUB>L</SUB>) for stormwater treatment. </LI> <LI> Selective sorption for copper, cadmium, and zinc in the presence of calcium. </LI> <LI> Reusability likely due to structure stability of disulfide linked polymer networks. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Multi-Secondary Transformer: A Modeling Technique for Simulation - II

Patel, A.,Singh, N.P.,Gupta, L.N.,Raval, B.,Oza, K.,Thakar, A.,Parmar, D.,Dhola, H.,Dave, R.,Gupta, V.,Gajjar, S.,Patel, P.J.,Baruah, U.K. Journal of International Conference on Electrical 2014 Journal of international Conference on Electrical Vol.3 No.1

Power Transformers with more than one secondary winding are not uncommon in industrial applications. But new classes of applications where very large number of independent secondaries are used are becoming popular in controlled converters for medium and high voltage applications. Cascade H-bridge medium voltage drives and Pulse Step Modulation (PSM) based high voltage power supplies are such applications. Regulated high voltage power supplies (Fig. 1) with 35-100 kV, 5-10 MW output range with very fast dynamics (${\mu}S$ order) uses such transformers. Such power supplies are widely used in fusion research. Here series connection of isolated voltage sources with conventional switching semiconductor devices is achieved by large number of separate transformers or by single unit of multi-secondary transformer. Naturally, a transformer having numbers of secondary windings (~40) on single core is the preferred solution due to space and cost considerations. For design and simulation analysis of such a power supply, the model of a multi-secondary transformer poses special problem to any circuit analysis software as many simulation softwares provide transformer models with limited number (3-6) of secondary windings. Multi-Secondary transformer models with 3 different schemes are available. A comparison of test results from a practical Multi-secondary transformer with a simulation model using magnetic component is found to describe the behavior closer to observed test results. Earlier models assumed magnetising inductance in a linear loss less core model although in actual it is saturable core made-up of CRGO steel laminations. This article discusses a more detailed representation of flux coupled magnetic model with saturable core properties to simulate actual transformers very close to its observed parameters in test and actual usage.

Three-Dimensional-Printed Titanium Versus Polyetheretherketone Cages for Lumbar Interbody Fusion: A Systematic Review of Comparative In Vitro, Animal, and Human Studies

Neal A. Patel,Sinead O’Bryant,Christopher D. Rogers,Sachiv Chakravarti,Julian Gendreau,Nolan J. Brown,Zach A. Pennington,Neill B. Hatcher,Luis Daniel Diaz-Aguilar,Martin H. Pham 대한척추신경외과학회 2023 Neurospine Vol.20 No.2

Interbody fusion is a workhorse technique in lumbar spine surgery that facilities indirect decompression, sagittal plane realignment, and successful bony fusion. The 2 most commonly employed cage materials are titanium (Ti) alloy and polyetheretherketone (PEEK). While Ti alloy implants have superior osteoinductive properties they more poorly match the biomechanical properties of cancellous bones. Newly developed 3-dimensional (3D)-printed porous titanium (3D-pTi) address this disadvantage and are proposed as a new standard for lumbar interbody fusion (LIF) devices. In the present study, the literature directly comparing 3D-pTi and PEEK interbody devices is systematically reviewed with a focus on fusion outcomes and subsidence rates reported in the in vitro, animal, and human literature. A systematic review directly comparing outcomes of PEEK and 3D-pTi interbody spinal cages was performed. PubMed, Embase, and Cochrane Library databases were searched according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. Mean Newcastle-Ottawa Scale score for cohort studies was 6.4. A total of 7 eligible studies were included, comprising a combination of clinical series, ovine animal data, and in vitro biomechanical studies. There was a total population of 299 human and 59 ovine subjects, with 134 human (44.8%) and 38 (64.4%) ovine models implanted with 3D-pTi cages. Of the 7 studies, 6 reported overall outcomes in favor of 3D-pTi compared to PEEK, including subsidence and osseointegration, while 1 study reported neutral outcomes for device related revision and reoperation rate. Though limited data are available, the current literature supports 3D-pTi interbodies as offering superior fusion outcomes relative to PEEK interbodies for LIF without increasing subsidence or reoperation risk. Histologic evidence suggests 3DTi to have superior osteoinductive properties that may underlie these superior outcomes, but additional clinical investigation is merited.

Free Tissue Transfer in Sickle Cell Disease: A Case Report and Systematic Review

Huang Anne,Patel Ronak A.,Gottlieb Lawrence J. 대한성형외과학회 2023 Archives of Plastic Surgery Vol.50 No.3

Hemoglobinopathies such as sickle cell disease (SCD) are traditionally considered a relative contraindication to free tissue transfer, due to concerns that erythrocyte sickling will increase the risk of microvascular thrombosis and flap failure. This article describes a case report with the successful use of free tissue transfer in a patient with SCD and provides a systematic literature review on free tissue transfer in SCD. A retrospective chart review was performed of a patient with SCD who underwent free tissue transfer at the authors' institution. A systematic literature review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed using the keywords “free tissue transfer,” “free flap,” or “microsurgery” and “sickle cell” on PubMed, Ovid/Medline, and Scopus. A 29-year-old male with delayed presentation of an electrical burn to the face and scalp underwent wound closure with a free anterolateral thigh flap. Key management principles included red blood cell transfusion to keep hemoglobin S under 30% and hemoglobin greater than 10 g/dL, maintenance of hydration, normothermia, adequate analgesia, and postoperative anticoagulation. Systematic literature review identified 7 articles describing 13 cases of free tissue transfer in 10 patients with SCD, with combined complete free flap success in 10 of the 13 flaps. Free tissue transfer can be successfully performed in patients with SCD. However, evidence on the optimal management of this unique patient population in the perioperative period after free tissue transfer is limited to case reports in the literature.

Spinal Epidermoid Tumors: Case Report and Review of the Literature

Vivek B. Beechar,Pascal O. Zinn,Kent A. Heck,Gregory N. Fuller,한인보,Akash J. Patel,Alexander E. Ropper 대한척추신경외과학회 2018 Neurospine Vol.15 No.2

Spinal epidermoid tumors are rare, benign tumors that are either acquired from trauma, surgery, or lumbar puncture or arise as congenital lesions, particularly spinal dysraphisms. We report a case of a massive spinal epidermoid tumor and review the literature with a focus on the surgical outcomes. A 71-year-old female patient presented after a fall with subsequent symptoms of severe back and hip pain, as well as loss of motor strength in the left leg. Her magnetic resonance imaging demonstrated a T2/short tau inversion recovery hyperintense mass extending from the level of the T10–11 disc caudally through S2. A biopsy was recommended to determine whether the tumor was radio- or chemo-sensitive. The patient underwent a L4 laminectomy and a pearly-white tumor was encountered, with a subsequent biopsy confirming it to be an epidermoid tumor. The following conclusions can be drawn from a review of the literature. Spinal epidermoid tumors are more common in women and tend to present in younger patients (median age of 23). The majority of patients had acquired lesions (46%). In terms of surgical outcomes for adherent tumors, gross total resection was found to provide optimal outcomes, with 90% of patients improving clinically after surgery.

Swallowing Function Following Anterior Cervical Discectomy and Fusion With and Without Anterior Plating: A SWAL-QOL (Swallowing-Quality of Life) and Radiographic Assessment

Brittany E. Haws,Benjamin Khechen,Dil V. Patel,Joon S. Yoo,Jordan A. Guntin,Kaitlyn L. Cardinal,Kern Singh 대한척추신경외과학회 2019 Neurospine Vol.16 No.3

Objective: Anterior cervical plating in anterior cervical discectomy and fusion (ACDF) procedures are associated with improved outcomes compared to stand-alone cages. However, concerns exist regarding increased rates of postoperative dysphagia following an ACDF. This study aims to quantify the effect of anterior plating on swallowing-quality of life (SWAL-QOL) scores and radiographic swelling assessments following a primary, single-level ACDF. Methods: Patients retrospectively reviewed. Patients grouped into those receiving a cage or anterior plate. SWAL-QOL scores were recorded preoperatively and 6 weeks and 12 weeks postoperatively. Lateral radiographs were used to create a swelling index with a ratio of the prevertebral swelling distance to the anterior-posterior diameter of each involved vertebral body. An air index was created using the same methodology. Statistical analysis was performed using chi-square analysis and independent t-tests for categorical and continuous variables. Results: Sixty-eight primary, single-level ACDF patients were included. Forty-one (60.3%) received a stand-alone cage and 27 (39.7%) received a cage with anterior plating. No differences in demographics, comorbidities, operative time, estimated blood loss, or length of hospital stay were identified between Cage and Plate cohorts. Finally, no differences were observed in postoperative SWAL-QOL scores or swelling and air indices between groups. Conclusion: The results demonstrate that patients undergoing a primary, single-level ACDF with or without anterior plating experience similar operative times and lengths of stay. Patients that receive a cage with anterior plating did not experience significant increases in dysphagia as measured by the SWAL-QOL questionnaire compared to patients that received a stand-alone cage. Furthermore, radiographic assessments of swelling are comparable.

Nanoporous Benzoxazole Networks by Silylated Monomers, Their Exceptional Thermal Stability, and Carbon Dioxide Capture Capacity

Patel, Hasmukh A.,Ko, Dongah,Yavuz, Cafer T. American Chemical Society 2014 Chemistry of materials Vol.26 No.23

<P>The pursuit of synthetic routes for design and preparation of nanoporous polymeric networks with inherent permanent microporosity and functionality through bottom-up methodologies remains a driving force in developing CO<SUB>2</SUB>-philic materials. We report nanoporous, processable, benzoxazole-linked covalent organic polymers (Box-COPs) that show exceptional thermal stability up to 576 °C. Box-COPs can be formed into films thanks to the silylation that is used to guide polymeric network formation. Surface areas of up to 606 m<SUP>2</SUP> g<SUP>–1</SUP> and narrow pore sizes of 4.36 Å were observed with a CO<SUB>2</SUB> uptake capacity of 139.6 mg g<SUP>–1</SUP> at 273 K and 1 bar. Box-COPs were stable in boiling water for a week without deteriorating CO<SUB>2</SUB> capture capacity.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2014/cmatex.2014.26.issue-23/cm503627p/production/images/medium/cm-2014-03627p_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm503627p'>ACS Electronic Supporting Info</A></P>

Highly Stable Nanoporous Sulfur‐Bridged Covalent Organic Polymers for Carbon Dioxide Removal

Patel, Hasmukh A.,Karadas, Ferdi,Byun, Jeehye,Park, Joonho,Deniz, Erhan,Canlier, Ali,Jung, Yousung,Atilhan, Mert,Yavuz, Cafer T. WILEY‐VCH Verlag 2013 Advanced Functional Materials Vol.23 No.18

<P><B>Abstract</B></P><P>Carbon dioxide capture and separation requires robust solids that can stand harsh environments where a hot mixture of gases is often found. Herein, the first and comprehensive syntheses of porous sulfur‐bridged covalent organic polymers (COPs) and their application for carbon dioxide capture in warm conditions and a wide range of pressures (0–200 bar) are reported. These COPs can store up to 3294 mg g<SUP>−1</SUP> of carbon dioxide at 318 K and 200 bar while being highly stable against heating up to 400 °C. The carbon dioxide capacity of the COPs is also not hindered upon boiling in water for at least one week. Physisorptive binding is prevalent with isosteric heat of adsorptions around 24 kJ mol<SUP>−1</SUP>. M06–2X and RIMP2 calculations yield the same relative trend of binding energies, where, interestingly, the dimer of triazine and benzene play a cooperative role for a stronger binding of CO<SUB>2</SUB> (19.2 kJ mol<SUP>−1</SUP>) as compared to a separate binding with triazine (13.3 kJ mol<SUP>−1</SUP>) or benzene (11.8 kJ mol<SUP>−1</SUP>).</P>