Protective efficacy of Coriandrum sativum seeds against arsenic induced toxicity in Swiss albino mice

Kumar Arun,Kumar Vikas,Akhouri Vivek,Kumar Ranjit,Ali Mohammad,Rashmi Tuhin,Chand Gyanendra Bahadur,Singh Sushil Kumar,Ghosh Ashok Kumar 한국독성학회 2022 Toxicological Research Vol.38 No.4

Arsenic poisoning in ground water is one of the most sensitive environmental pollutant causing serious pollution all over the world. Chronic arsenic exposure through drinking water to humans leads to major public health related issues. There have been very meagre studies which reported that, the plant constituents proved to exhibit protective effect from arsenicosis. Therefore, the present study aims to evaluate the protective efficacy of Coriandrum sativum seeds extract against sodium arsenite induced toxicity in Swiss albino mice. In the present study twenty-four male healthy Swiss albino mice (30 ± 5 g) were divided into four groups (n = 6), where the control group received normal diet and water; group II and group III treated with sodium arsenite (2 mg per kg body weight per day) for 2 and 4 weeks respectively. The group IV mice were administered with C.sativum seeds extract at the dose of 150 mg per kg body weight per day for 4 weeks upon sodium arsenite pretreated (2 mg/kg body weight for 4 weeks per day) mice. After the complete dose duration, all the treatment group animals were sacrificed same day for haematological, biochemical and histopathological study. In the arsenic treated mice, there were significant (p < 0.0001) changes in the serum levels of ALT, AST, ALP, urea, uric acid and creatinine as well as in the haematological parameters. In contrast, after the administration with C.sativum seeds extract upon arsenic pretreated mice, there was significant (p < 0.0001) improvement observed in the hepatic and renal biomarker parameters as well as haematological variables. In the arsenic intoxicated mice, after administration with C.sativum seeds extract there was significant (p < 0.0001) reduction in the arsenic concentration in blood, liver and kidney tissues as well as in the serum LPO levels. Furthermore, the histopathological study showed that, C.sativum seeds extract administrated group of mice significantly restored the liver and kidney at cellular level against arsenic induced toxicity. The entire study concludes that C.sativum seeds extract possesses the ameliorative effect against arsenic induced liver and kidney intoxication.

Ruptured mirror DACA aneurysm: A rare case report and review of literature

Deepak Kumar Singh,Prevesh Kumar Sharma,Arun Kumar Singh,Vipin Kumar Chand 대한뇌혈관외과학회 2023 Journal of Cerebrovascular and Endovascular Neuros Vol.25 No.3

Bilateral distal anterior cerebral artery (DACA) aneurysms also called “kissing aneurysms” or “mirror aneurysm” are extremely rare, accounting for only 0.2% of all intracranial aneurysms. There have only been a few examples of mirror DACA aneurysms reported in the literature. Here, we report a rare case of mirror DACA aneurysm in a middle aged female with its successful clipping. Patient was admitted with severe headache and altered sensorium. Computed tomography (CT) head was suggestive of anterior inter-hemispheric hematoma. Digital subtraction angiography (DSA) was done which was suggestive of two distal anterior cerebral artery aneurysms located at same anatomical position. It was treated through microsurgical clipping. Mirror image DACA aneurysms are rare occurrence. All patients with ruptured DACA aneurysms should have angiography with 3D reconstruction studies. This aids in determining the aneurysm’s morphology and planning treatment accordingly.

Molecular n-doping of chemical vapor deposition grown graphene

Singh, Arun Kumar,Iqbal, Muhammad Waqas,Singh, Vivek Kumar,Iqbal, Muhammad Zahir,Lee, Jae Hong,Chun, Seung-Hyun,Shin, Koo,Eom, Jonghwa The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.30

<P>It is essential to tailor the electronic properties of graphene in order to apply graphene films for use in electrodes. Here we report the modification of the electronic properties of single layer chemical vapor deposition (CVD) grown graphene by molecular doping without degrading its transparency and electrical properties. Raman spectroscopy and transport measurements revealed that <I>p</I>-toluenesulfonic acid (PTSA) imposes n-doping on single layer CVD grown graphene. The shift of G and 2D peak wave numbers and the intensity ratio of D and G peaks are analyzed as a function of reaction time. In the gate voltage dependent resistivity measurement, it is found that the maximum resistivity corresponding to the Dirac point is shifted toward a more negative gate voltage with increasing reaction time, indicating an n-type doping effect. We have also made single layer graphene p–n junctions by chemical doping and investigated the current–voltage characteristics at the p–n junction.</P> <P>Graphic Abstract</P><P>It is essential to tailor the electronic properties of graphene in order to apply graphene films for use in electrodes. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2jm32716c'> </P>

Negative Magnetoresistance in a Vertical Single-Layer Graphene Spin Valve at Room Temperature

Singh, Arun Kumar,Eom, Jonghwa American Chemical Society 2014 ACS APPLIED MATERIALS & INTERFACES Vol.6 No.4

<P>Single-layer graphene (SLG) is an ideal material for spintronics because of its high charge-carrier mobility, long spin lifetime resulting from the small spin–orbit coupling, and hyperfine interactions of carbon atoms. Here, we report a vertical spin valve with SLG with device configuration Co/SLG/Al<SUB>2</SUB>O<SUB>3</SUB>/Ni. We observed negative magnetoresistance (−0.4%) for the Co/SLG/Al<SUB>2</SUB>O<SUB>3</SUB>/Ni junction at room temperature. However, the Co/Al<SUB>2</SUB>O<SUB>3</SUB>/Ni junction, which is without graphene, shows positive magnetoresistance. The current–voltage (<I>I</I>–<I>V</I>) characteristics of both Co/SLG/Al<SUB>2</SUB>O<SUB>3</SUB>/Ni and Co/Al<SUB>2</SUB>O<SUB>3</SUB>/Ni junctions are nonlinear, and this reveals that charge transport occurs by a tunneling mechanism. We have also explained the reason for negative magnetoresistance for the Co/SLG/Al<SUB>2</SUB>O<SUB>3</SUB>/Ni junction.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-4/am4049145/production/images/medium/am-2013-049145_0006.gif'></P>

Hot stage microscopy and its applications in pharmaceutical characterization

Kumar Arun,Singh Pritam,Nanda Arun 한국현미경학회 2020 Applied microscopy Vol.50 No.1

Hot stage microscopy (HSM) is a thermal analysis technique that combines the best properties of thermal analysis and microscopy. HSM is rapidly gaining interest in pharmaceuticals as well as in other fields as a regular characterization technique. In pharmaceuticals HSM is used to support differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA) observations and to detect small changes in the sample that may be missed by DSC and TGA during a thermal experiment. Study of various physical and chemical properties such sample morphology, crystalline nature, polymorphism, desolvation, miscibility, melting, solid state transitions and incompatibility between various pharmaceutical compounds can be carried out using HSM. HSM is also widely used to screen cocrystals, excipients and polymers for solid dispersions. With the advancements in research methodologies, it is now possible to use HSM in conjunction with other characterization techniques such as Fourier transform infrared spectroscopy (FTIR), DSC, Raman spectroscopy, scanning electron microscopy (SEM) which may have additional benefits over traditional characterization techniques for rapid and comprehensive solid state characterization.

Negative Magnetoresistance in a Vertical Single-Layer Graphene Spin Valve at Room Temperature

Singh, Arun Kumar,Eom, Jonghwa American Chemical Society 2014 ACS APPLIED MATERIALS & INTERFACES Vol.6 No.4

Single-layer graphene (SLG) is an ideal material for spintronics because of its high charge-carrier mobility, long spin lifetime resulting from the small spin orbit coupling, and hyperfine interactions of carbon atoms. Here, we report a vertical spin valve with SLG with device configuration Co/SLG/Al2O3/Ni. We observed negative magnetoresistance (-0.4%) for the Co/SLG/Al2O3/Ni junction at room temperature. However, the Co/Al2O3/Ni junction, which is without graphene, shows positive magnetoresistance. The current voltage (I V) characteristics of both Co/SLG/Al2O3/Ni and Co/Al2O3/Ni junctions are nonlinear, and this reveals that charge transport occurs by a tunneling mechanism. We have also explained the reason for negative magnetoresistance for the Co/SLG/Al2O3/Ni junction.

Vision based rail track extraction and monitoring through drone imagery

Arun Kumar Singh,Anushka Swarup,Ankush Agarwal,Dharmendra Singh 한국통신학회 2019 ICT Express Vol.5 No.4

Track detection and gauge measurement are considered as crucial aspects of railway inspection systems. Traditionally, monitoring by human inspectors was done. Nowadays, computer vision-based systems are used due to their flexibility and ease of use. In recent years, various prototypes of vision based inspection system have been proposed, most have a camera mounted on carts or trains. Employing drones for such monitoring systems provides a cost effective and accurate means for monitoring tracks. This paper explores the possibilities of computer vision based monitoring through drone imagery. The experimental results ensure that the proposed method provides high reliability and accuracy.

Exploring the Utility of Vague Concept for Uncertainty and Hesitation Management

Arun Kumar Singh,Akhilesh Tiwari 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.12

In the realistic situation, there are many areas which contain imprecisely specified data. This imprecise data indicates the presence of vagueness, incompleteness and uncertainty which causes the problem during important decision-making task. The present paper focuses on the problem of mining important inference from supermarket basket data (in the presence of vagueness). The paper specifically studies the usefulness of vague set theory for the exploration of hesitation information and vague association rules. The hesitation information of an item plays a vital role in making selling strategies for the exhilaration of business. For this purpose, the vague set concept can be used as an important tool which can assist in the identification of hesitated item. The vague set theory with its two membership function provides more intuitive way to interact with the vague situation that causes the hesitation for any item. The effectiveness of the hesitated pattern and rule provide advanced decision-making capabilities that transform ‘almost sold’ items to ‘sold items’.

Tailoring the Electrical Properties of Graphene Layers by Molecular Doping

Singh, Arun Kumar,Ahmad, Muneer,Singh, Vivek Kumar,Shin, Koo,Seo, Yongho,Eom, Jonghwa American Chemical Society 2013 ACS APPLIED MATERIALS & INTERFACES Vol.5 No.11

<P>It is an essential issue in graphene-based nanoelectronic and optoelectronic devices to tune the electrical properties of graphene layers, while preserving its unique band structure. Here, we report the tuning of electronic properties of single-, bi-, and trilayer mechanically exfoliated graphenes by <I>p</I>-toluenesulfonic acid (PTSA) molecular doping. Raman spectroscopy and charge transport measurements revealed that PTSA molecule imposes <I>n</I>-doping to single-, bi-, and trilayer graphenes. The shift of G and 2D peak frequencies and intensity ratio of single-, bi-, and trilayer graphenes are analyzed as a function of reaction time. The Dirac point is also analyzed as a function of reaction time indicates the <I>n</I>-type doping effect for all single-, bi-, and trilayer graphenes. Our study demonstrates that chemical modification is a simple approach to tailor the electrical properties of single-, bi-, and trilayer graphenes, while maintaining the important electrical assets.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2013/aamick.2013.5.issue-11/am401119j/production/images/medium/am-2013-01119j_0008.gif'></P>

Low-Voltage and High-Performance Multilayer MoS₂ Field-Effect Transistors with Graphene Electrodes

Singh, Arun Kumar,Hwang, Chanyong,Eom, Jonghwa American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.50

<P>Atomically thin two-dimensional (2D) materials are attractive because they have excellent material properties and channel length scalability. Fabrication of complex structures from these materials is also relatively easy. Accordingly, 2D materials such as molybdenum disulfide (MoS2) have been intensively studied because of their novel properties for advanced electronics and optoelectronics. This study realizes the low-voltage and high-performance field-effect transistors with chemical vapor deposition-grown single layer graphene employed as the thinnest electrode and semiconducting multilayer (ML) MoS2 utilized as a channel material. The two-terminal mobility of graphene-contacted ML MoS2 using 15 nm Al2O3 as the top-gate dielectric layer is 131.2 cm(2)/(V s) at room temperature, which is higher than that of the previously reported metal/graphene-contacted MoS2. The result demonstrates that van der Waals bonding at the graphene-MoS2 interfaces and high-k dielectric provide an important step toward the realization of high-performance and low-voltage thin-film transistors.</P>