Rapidly Synthesized, Few-Layered Pseudocapacitive SnS₂ Anode for High-Power Sodium Ion Batteries

Thangavel, Ranjith,Samuthira Pandian, Amaresh,Ramasamy, Hari Vignesh,Lee, Yun-Sung American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.46

<P>The abundance of sodium resources has recently motivated the investigation of sodium ion batteries (SIBs) as an alternative to commercial lithium ion batteries. However, the low power and low capacity of conventional sodium anodes hinder their practical realization. Although most research has concentrated on the development of high-capacity sodium anodes, anodes with a combination of high power and high capacity have not been widely realized. Herein, we present a simple microwave irradiation technique for obtaining few layered, ultrathin two-dimensional SnS2 over graphene sheets in a few minutes. SnS2 possesses a large number of active surface sites and exhibits high-capacity, rapid sodium ion storage kinetics induced by quick, nondestructive pseudocapacitance. Enhanced sodium ion storage at a high current density (12 A g(-1)), accompanied by high reversibility and high stability, was demonstrated. Additionally, a rationally designed sodium ion full cell coupled with SnS2//Na3V2(PO4)(3) exhibited exceptional performance with high initial Coulombic efficiency (99%), high capacity, high stability, and a retention of similar to 53% of the initial capacity even after the current density was increased by a factor of 140. In addition, a high specific energy of similar to 140 Wh kg(-1) and an ultrahigh specific power of 8.3 kW kg(-1) (based on the mass of both the anode and cathode) were observed. Because of its outstanding performance and rapid synthesis, few-layered SnS2 could be a promising candidate for practical realization of high-power SIBs.</P>

High performing sodium hybrid capacitor with super-ionic conductor NaTi₂(PO₄)₃

공민경,( Thangavel Ranjith ),김소영,( Hari Vignesh Ramasamy ),박주연,( Balasubramaniam Ramkumar ),김현재,정강현,이윤성 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

We have developed a new high performing sodium hybrid capacitor (NHC) using sodium super ionic conductor NaTi₂(PO₄)₃ grown on graphene sheets (GNTP) and capacitor type carbon electrode in an organic electrolyte. The hybrid device works on two charge storage reactions that occurs simultaneously, sodium ion intercalation/deintercalation into GNTP, providing high energy, and adsorption/desorption of anion over the pores of carbon provides high power. A high energy density of 80 Wh kg^-1 has been achieved at a specific power of Additionally, the hybrid capacitor retains 32 Wh kg^-1 of energy at high specific power of 8 kW kg^-1, outperforming lithium hybrid capacitors. An outstanding stability of 90% has been achieved even after 75,000 cycles. The combination of high energy at high power along with high stability emerge them as a suitable candidate for next generation high power devices.

Surface modification using atomic layer deposition for developing high voltage sodium layered oxides

공민경,( Hari Vignesh Ramasamy ),( Thangavel Ranjith ),김소영,박주연,( Balasubramaniam Ramkumar ),이윤성 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Here, we present a comprehensive study on the influence of ultrathin metal oxide coating for developing high voltage sodium layered oxides using Atomic Layer Deposition (ALD). Detailed structural, morphological, and electrochemical investigations were carried out using X-ray diffraction, cyclic voltammetry, and galvanostatic charge-discharge measurements. The ALD modified electrode exhibits exceptional stability of above 80% for 100 cycles within a 2.0-4.5V window, and outperforms several other Mn-based cathodes for SIBs. Our work presents new insights for designing structurally stable cathode for Sodium Ion Batteries (SIBs).

Designing stable layered cathode material for sodium ion batteries by Aluminium doping

공민경,( Hari Vignesh Ramasamy ),( Thangavel Ranjith ),김소영,박주연,( Balasubramaniam Rankumar ),성원모,강기석,이윤성 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Here, we present a comprehensive study on the influence of Al doping of Mn sites on the structural and electrochemical properties of a P2-Na_0.5Mn_0.5-xAl_xCo_0.5O₂ (x = 0, 0.02, or 0.05) cathode for SIBs. Detailed structural, morphological, and electrochemical investigations were carried out using X-ray diffraction, cyclic voltammetry, and galvanostatic charge-discharge measurements and some new insights are proposed. Rietveld refinement confirmed that Al doping caused TMO₆-octahedra (TM= Transition metal) shrinkage, resulting in wider interlayer spacing. After optimizing the aluminum concentration, the cathode exhibited remarkable electrochemical performance, with better stability and improved rate performance. The material presented here exhibits exceptional stability over 100 cycles within a 1.5-4.3 V window, and outperforms several other Mn-Co-based cathodes for SIBs.

SARS-CoV-2 in the Prostate: Immunohistochemical and Ultrastructural Studies

Reddy Rohit,Farber Natoli,Kresch Eliyahu,Seetharam Deepa,Diaz Parris,Ramasamy Ranjith 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.2

The novel coronavirus SARS-CoV-2 was discovered in 2019 and has proven to be a significant public health challenge. While viruses from the coronavirus family have been established as causes of respiratory tract infections, SARS-CoV-2 has also been found in the heart, kidney, testes, and penis. This paper investigates whether SARS-CoV-2 can linger in the prostate by examining the histopathological, ultrastructural, and immunofluorescent elements of prostatic tissue from a patient who was infected by the SARS-CoV-2 virus prior to having a holmium laser enucleation of the prostate (HoLEP) procedure. The findings of this case report suggest that COVID-19 has both the ability to enter prostatic tissue during an acute infection and persist over a timeframe beyond the initial infection period as RNA-containing viral bodies. This case report lays the founda-tion for future investigations to examine any histopathological changes to the prostatic tissue that may be associated with SARS-CoV-2 viral infection.

Elevated Body Mass Index Is Associated with Secondary Hypogonadism among Men Presenting to a Tertiary Academic Medical Center

John M. Masterson,Nachiketh Soodana-Prakash,Amir S. Patel,Atil Y. Kargi,Ranjith Ramasamy 대한남성과학회 2019 The World Journal of Men's Health Vol.37 No.1

Purpose: To characterize the population of hypogonadal men who presented to a tertiary academic urology clinic and evalu-ate risk factors for primary vs. secondary hypogonadism. Materials and Methods: We evaluated all men with International Classification of Diseases-9 diagnosis codes R68.82 and 799.81 for low libido, 257.2 for testicular hypofunction, and E29.1 for other testicular hypofunction at a tertiary academic medical center from 2013 to 2017. We included men who had testosterone (T) and luteinizing hormone (LH) drawn on the same day. We classified men based on T and LH levels into eugonadal, primary, secondary, and compensated hypogonad-ism. Risk factors including age, body mass index (BMI) over 30 kg/m2, current smoking status, alcohol use greater than 5 days per week, and Charlson comorbidity index greater than or equal to 1 were investigated and measured in each group using the eugonadal group for reference. Results: Among the 231 men who had both T and LH levels, 7.4%, 42.4%, and 7.4% were classified as primary, secondary, and compensated hypogonadism, respectively. Only elevated BMI was associated with secondary hypogonadism compared to eugonadal men (median BMI, 30.93 kg/m2 vs. 27.69 kg/m2, p=0.003). BMI, age, comorbidities, smoking, or alcohol use did not appear to predict diagnosis of secondary hypogonadism. Conclusions: Secondary hypogonadism appears to be the most common cause of hypogonadism among men complaining of low T and decreased libido at a tertiary academic medical center. Secondary hypogonadism is associated with elevated BMI and therefore obesity should be used as a marker to evaluate men for both T and LH levels.

Clinical Update on Home Testing for Male Fertility

Gonzalez Daniel,Narasimman Manish,Best Jordan C.,Ory Jesse,Ramasamy Ranjith 대한남성과학회 2021 The World Journal of Men's Health Vol.39 No.4

Male factor infertility accounts for about 50% of the incidence of infertility in couples. In current practice, the men must attend a clinic or hospital facility to provide a semen analysis, which is key to the diagnosis of the male reproductive potential. However, many men are often embarrassed with the process and conventional semen analysis requires complex, labor intensive inspection with a microscope. To mitigate these problems, one of the solutions can be at-home semen analysis. In this review we examine the literature of currently available at home semen analysis test kits, describe their limitations, and compare them to the conventional lab-based methods.

Survey of Microsurgery Training Availability in US Urology Residency Programs

Masterson Thomas A.,Nackeeran Sirpi,Rainer Quinn,Hauser Nicholas,Marcovich Robert,Ramasamy Ranjith 대한남성과학회 2021 The World Journal of Men's Health Vol.39 No.2

Purpose: The Accreditation Council of Graduate Medical Education (ACGME) establishes surgical minimum numbers of cases for urologic training. Currently there is not a requirement for microsurgery, likely from a belief that programs do not offer exposure. In an effort to evaluate the availability of microsurgery training among urology residency programs we surveyed the programs. Materials and Methods: We obtained a list of the 138 ACGME-accredited urology residencies and contact information the American Urology Association (AUA). We contacted the residency programs by phone and e-mail. For programs that did not reply, we performed a search of the program website. We answered 3-questions to assess resident subspecialty training in microsurgery and used penile implant and artificial urinary sphincters as a comparison. Data are reported as frequencies. Results: We obtained data from 134 programs (97.1%). A total of 104 programs (77.6%) had fellowship-trained physicians for training in microsurgery, 86.6% for penile implants, and 88.8% for artificial urinary sphincters. The percentage of fellowshiptrained microsurgeons per program did not vary significantly when comparing the different sections of the AUA. The northeast and southeast sections had the lowest percentage (67% and 68%). Conclusions: Nearly 80% of urology residency programs have a fellowship-trained microsurgeon on faculty, we therefore believe that microsurgery should be added as part of the ACGME minimums. In order to provide an equal exposure to all graduating urology residents, urology residency programs that lack microsurgery should identify potential faculty with fellowship training.

Testosterone Is a Contraceptive and Should Not Be Used in Men Who Desire Fertility

Amir Shahreza Patel,Joon Yau Leong,Libert Ramos,Ranjith Ramasamy 대한남성과학회 2019 The World Journal of Men's Health Vol.37 No.1

Testosterone has a variety of functions and is commonly used in older men to treat symptoms of hypogonadism, such as decreased libido, decreased mood and erectile dysfunction. Despite its positive effects on sexual function, it has a negative effect on fertility. Exogenous testosterone therapy can negatively affect the hypothalamic-pituitary gonadal axis and inhibit the production of follicle stimulating hormone and luteinizing hormone. The purpose of this review is to discuss the contra-ceptive properties of testosterone therapy and to discuss strategies to increase testosterone in men with the desire to preserve fertility.

Advanced Paternal Age and Sperm DNA Fragmentation: A Systematic Review

Gonzalez Daniel C.,Ory Jesse,Blachman-Braun Ruben,Nackeeran Sirpi,Best Jordan C.,Ramasamy Ranjith 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.1

Purpose: Male ageing is often associated with defective sperm DNA remodeling mechanisms that result in poorly packaged chromatin and a decreased ability to repair DNA strand breaks. However, the impact of advanced paternal age on DNA fragmentation remains inconclusive. The aim of the present systematic review was to investigate the impact of advancing paternal age (APA) on DNA fragmentation. Materials and Methods: We conducted a thorough search of listed publications in Scopus, PubMed, and EMBASE, in accordance with the PRISMA guidelines. Results: We identified 3,120 articles, of which nineteen were selected for qualitative analysis, resulting in a sample of 40,668 men. Of the 19 articles evaluating the impact of APA on DFI% (DNA fragmentation Index) included, 4 were on Normozoospermic and subfertile men, 3 on normozoospermic, Oligoasthenoteratozoospermic and Teratozoospermic, 6 on fertile and infertile men, 4 on just infertile men, and 2 evaluated a general population. Seventeen of the ninrnteen studies demonstrated APA’s effect and impact on DFI%. Conclusions: Although there was no universal definition for APA, the present review suggests that older age is associated with increased DFI. In elderly men with normal semen parameters, further studies should be performed to assess the clinical implications of DFI, as a conventional semen analysis can often fail to detect an etiology for infertility.