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A simple hydrothermal method was used to prepare palladium-doped few-layer molybdenum disulfide nanosheets grown on the surface of a multi-walled carbon nanotube (Pd–MoS2/CNT) with forming a three-dimensional (3D) hierarchical core-shell heterostructure. This paper provides first-hand information on electromagnetic interference (EMI) scattering and electromagnetic (EM) parameters in the X-band (8–12 GHz) microwave frequency range. In this hierarchical core-shell heterostructure, SEM and TEM photos clearly show that CNT forms the core, while Pd-doped few layers MoS2 grown on the surface of CNT is the shell. The Pd-doped MoS2/CNT nanohybrids can greatly improve electrical conductivity, defect dipole polarization, interfacial polarization, dielectric relaxation loss, and mobile charge carriers between core and shell. These are the reason for the substantial enrichment in EMI shielding effectiveness (SE) and dielectric performance. The 10% Pd–MoS2/CNT nanohybrid has a higher EMI SE and dielectric loss tangent (SET ~ 26.50 dB, tan δ e ~2.37) than the 5% Pd–MoS2/CNT (SET ~ 22.50 dB, tan δ e ~1.90) and undoped MoS2/CNT (SET ~ 21.55 dB, tan δ e ~0.92) at the same thickness of 1 mm. The strong EMI SE and dielectric loss tangent are found due to their higher dipole polarization, conduction, and relaxation losses. The doping concentration of Pd-atoms has a significant impact on EM parameters (e′, e″, μ′ & μ″) and EMI scattering parameters (S11, S21, S12 & S22). The experimental results indicated that the 10% Pd–MoS2/CNT nanohybrid might be considered a good EMI shielding and dielectric material for large scale use in intelligence wireless information and communication devices in the future.

In this study, a three-dimensional (3D) micro-flower like morphology aluminum-doped molybdenum disulfide/reduced graphene oxide (Al@MoS2/rGO) nanohybrids have been developed using a simple and sensitive hydrothermal approach. Their electromagnetic (EM) parameters (permittivity, permeability) and microwave shielding parameters (S11, S12) have been analyzed and reported for the first time in the microwave frequency range of 8.0–12.0 GHz. It is interesting to note that the electrical conductivity of the nanohybrids increases with the doping concentration of Al-ions, whereas skin-depth has a reverse trend. The 12% Al@MoS2/rGO nanohybrid shows a higher total electromagnetic interference shielding effectiveness (EMI SE) value about SET ~33.38 dB, whereas undoped MoS2/rGO nanohybrid exhibits a lower value around ~17.07 dB at the same thin thickness. The higher doping concentration of Al-ion creates lattice distortion and crystal defects with high charge carrier mobility between multiple interfaces and at defective sites. Hence, the Al-doping into MoS2 lattice supported on the rGO surface can greatly enhance EM wave absorption and EMI SE value. The present work suggests that the 12% Al@MoS2/rGO nanohybrid can be treated as a good microwave absorbing and shielding material and useful in various techno-commercial devices.

Uric acid (UA) level quantification is crucial for the diagnosis and treatment of cardiovascular, arthritis, renal disorder, and preeclampsia diseases. We report the solvent-assisted synthesis of zinc oxide (ZnO) nanoparticles (NPs) which we used to make a seed layer on a conductive fluorine-doped tin oxide (FTO) electrode. Vertically-arranged ZnO nanorods (NRs) were grown using a hydrothermal method. The ZnO NPs and NRs were characterized in detail, which revealed the smaller sizes (10–15 nm) of the NPs and the vertically-arranged nature of the NRs. Furthermore, a highly sensitive UA biosensor was constructed with vertically-arranged ZnO NRs. The electrochemical characterization of the UA biosensor (Nafion/uricase/ZnO NRs–ZnO NPs/FTO) using differential pulse voltammetry (DPV) demonstrated linearity over a wide UA concentration range (0.01–1.5 mM) with a high sensitivity (345.44 μA mM−1 cm−2) and limit of detection (LOD; 2.5 μM). The biosensor also showed good selectivity, high reproducibility, and enhanced shelf-life. Additionally, practical feasibility was tested in a real (i.e., human blood serum) sample. The boosted UA biosensor performance is attributed to the vertically-arranged ZnO NRs, which immobilize a large amount of enzyme owing to their high surface-to-volume ratio, compared to flat surface-based biosensors. The present strategy, using vertically-arranged ZnO NRs on NP-seeded electrodes, can be extended to fabricate different ZnO NR-based chemical/biosensing devices.

In this paper, Co-doped molybdenum disulfide anchored on the surface reduced graphene oxide (Co@MoS2/rGO) has been successfully synthesized using a simple and effective hydrothermal approach to measure their microwave shielding properties. The X-ray diffraction (XRD) technique confirmed the successful doping of magnetic atoms into the MoS2 lattice. The experiments show that 15% and 20% Co@MoS2/rGO nanocomposite have higher electromagnetic interference shielding effectiveness (EMI SE) value up to SET ~ 38.26 and ~ 46.02 dB, respectively. But pure MoS2/rGO nanocomposite demonstrates a lower EMI SE value of around ~ 28.90 dB over the frequency range of 8.0–12.0 GHz with a 1.7 mm thickness. A higher value of the EMI SE depends mainly on the doping percentage of Co-ion. This nanocomposite network enhances the defect dipole polarization, electric conduction, interfacial polarization, and impedance matching characteristics. It is favorable for strong attenuation and dissipation loss ability of microwave energy inside the shielding material. The actual role of Co-doping is to form a highly conductive and magnetic channel between multi-interfaces leading to enhance the migration and hopping of electrons at defective sites or interface. Therefore, the 20% Co@MoS2/rGO nanocomposite is considered as novel microwave shielding material and can be widely used in electronic information and communication devices.

Electromagnetic interference (EMI) pollution has now become a subject of great concern with the rapid development of delicate electronic equipment in commercial, civil, and military operations. There has been a surge in pursuit of light-weight, adaptable, effective, and efficient EMI screening materials in recent years. The present article addresses a simple and sensitive approach to synthesize a core/shell carbon nanotube/MoS2 heterostructure supported on reduced graphene oxide (CNT/MoS2-rGO nanohybrid) as an efficient electromagnetic shielding material. The structural and morphological characteristics were accessed through X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy, augmenting successful formation of the CNT/MoS2-rGO nanohybrid. The shielding performance of the as-synthesized samples has been accessed in a wide frequency range of 8-12 GHz. A CNT/MoS2-rGO nanohybrid demonstrates a better EMI shielding performance in comparison to MoS2 nanosheets and MoS2-rGO nanohybrid individually. The CNT/MoS2-rGO nanohybrid having a thickness ∼1 mm shows excellent total shielding effectiveness (SET) as high as 40 dB, whereas MoS2 and MoS2-rGO hybrid lags far, with the average value of SET as 7 and 28 dB, respectively. It also demonstrates that the nanohybrid CNT/MoS2-rGO shields the EM radiation by means of absorption through several functional defects and multiple interfaces present in the heterostructure. Herein, we envision that our results provide a simple and innovative approach to synthesize the light-weight CNT/MoS2-rGO nanohybrid having flexibility and high shielding efficiency and widen its practical applications in stealth technology.

Small intestinal obstruction is one of the most common abdominal emergency faced by surgery resident in emergency department. Diagnosis and management of these patients are challenging as underlying pathology is usually obscure and disease is associated with significant morbidity and mortality. Aims: in this study it was aimed to evaluate the common etiological factor related to small bowel obstruction in adult patients in our setting as our centre is the only tertiary care centre belongs to Kumaun region at present and also deal the patients from various nearby districts of state of Uttar Pradesh (the most populated state of India) like Moradabad, Rampur, Bijnor, Bareilly and Badanyu, most of these patient are from low socioeconomical strata of their region. Methods: our study was a retrospective analytic study. The data of adult patients who had surgical intervention for small bowel obstruction in the general surgery department of Dr. Sushila Tiwari Govt. hospital attached to GMC Haldwani, between 2014 and 2019 was evaluated retrospectively. All data of patients above age 14 year was collected which includes mainly information about age, additional morbidity and operative notes. Results: there were total 191 patients operated during this time span for small intestinal obstruction, out of these, 82 were female and 119 were male. Patients from 4’Th decades (25.13%) of their life were most commonly affected. Abdominal tuberculosis was most common etiology found in 30.89% patient, follow by post-operative adhesion, Hernias and malignancy respectively. Conclusions: The causes of intestinal obstruction are variable in different parts of the world. Tuberculosis was the leading cause of small intestinal obstruction in this study.

Dilute magnetic semiconductor quantum dots (DMSQDs) have emerged as potential materials for future spin-based technologies. A critical parameter for the development of this technology is a relative...

Herein, we reported the electromagnetic interference performance of NiFe2O4/rGO nanocomposite. In this study NiFe2O4 nanoparticles was synthesized by co-precipitation route and the magnetic nanoparticles were incorporated on reduced graphene oxide (rGO) using a solvothermal method. The detailed properties of synthesized materials were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), tunneling electron microscopy (TEM), Raman spectroscopy, vibrating sample magnetometer (VSM) system, and vector network analyzer (VNA). The electromagnetic interference (EMI) shielding property of composite materials was investigated in the 8.2–12.4 GHz (X-band) frequency region. The results depicted the significant dielectric and magnetic loss in the nanocomposite as compared to rGO. Consequently, composite has improved impedance matching characteristics, which required for high electromagnetic wave absorption. Moreover, the study showed that shielding effectiveness further improves with increasing nanoparticles concentration in nanocomposite, which is due to increased interconnected network between NiFe2O4 and rGO. Furthermore, total shielding effectiveness (SET) of (35/65) NiFe2O4/rGO nanocomposite of thickness 2 mm is 38.2 dB at 10.8 GHz, which is higher than the accompanying investigated sample. It could be inferred that the redeeming properties of high dielectric and magnetic loss, enhanced absorption and multiple reflections of (35/65) NiFe2O4/rGO nanocomposite resulted in high shielding effectiveness. Therefore, this result mean that NiFe2O4/rGO nanocomposite is a promising shielding material for application in microwave absorption appliances.

Copper (Cu) doped II–VI semiconductor quantum dots (QDs) manifest high luminescent dopant emission with excellent tunability. The Cu-doped II–VI QDs have been well studied via optical spectroscopy; nevertheless, the electrochemical study on doped QDs where the signals are traced to discover the absolute energies of dopant and band-edges of the host is rarely investigated. Herein, we have estimated these energies in 2 nm Cu-doped CdS QDs via cyclic voltammetry (CV). The CV graph of doped QDs revealed a specific intragap state where the redox potential is near to the Cu energy state. The observed results from the CV analysis were well correlated with optical spectra.

In the field of optoelectronics, all-inorganic CsPbBr3 perovskite nanocrystals (PNCs) have gained significant interest on account of their superb processability and ultra-high stability among all the counterparts. In this study, we conducted an in-depth analysis of CsPbBr3 PNCs using joint transient optical spectroscopies (time-resolved photoluminescence and ultrafast transient absorption) in a very comprehensive manner. In order to understand the in-depth analysis of excited-state kinetics, the transient absorption spectroscopy has been performed. The structure of interest of CsPbBr3 PNCs was subjected to the rates of the radiation energy of 0.10 mW (κr/κnr = ∼0.62) and 0.30 mW (κr/κnr = ∼0.64). With the rate of radiation energy 0.30 mW, it was observed that there was a significant increase in hot carrier relaxation together with high radiative recombination, resulting in a decrease in charge trappings. Herein, we demonstrate that the tuning of the rate of radiation energies helps to understand the charge-carrier kinetics of CsPbBr3 PNCs, which would thus improve the manufacturing of efficient photovoltaic devices.

Chemically prepared 0.5% iron (Fe) doped CdSe (Fe:CdSe) quantum dots (QDs) with a diameter of ∼3 nm and a wurtzite crystal structure are isolated. The oxidation state of Fe was confirmed by electron paramagnetic resonance (EPR) spectroscopy, from which it is evident that iron is in the Fe3+ oxidation state. The magnetic properties of Fe:CdSe QDs explored using a superconducting quantum interference device (SQUID) reveal multiple magnetic transitions. The DC magnetic susceptibility plot shows a low-temperature antiferromagnetism (AFM) transition observed below 25 K followed by another event occurring between 25 and ∼80 K. Further, the material shows superparamagnetic behaviour with a weak ferromagnetic exchange interaction as observed by field-dependent magnetization. At the lowest dopant concentration, we do not expect dopants to cluster or to form inclusions. Therefore, the observed magnetic behaviour is believed to be arising from the random substitution of the dopant ions and their magnetic exchange interaction with the CdSe host lattice.

The present book chapter highlights the potential of Hierarchical Nanostructured 3D Flowerlike BiOX (X=Cl, Br, I) microsphere as a remarkable technology towards the environmental remediation processes of various hazardous and persistent environmental pollutants. The work has emphasized the selected case studies on three-dimensional flowers like structures of Bismuth oxyhalides exclusively. The chapter also summarizes the selective synthesis and characterization domains of bismuth oxyhalides nanomaterials to better understand their assemblies and structures along with specific applications. A significant inside in the key challenges and future prospects associated with this technology has been also included in this chapter. &nbsp

Herein a one-step, easy, cheap and eco-friendly Solvothermal synthesis method has been used to synthesize monodisperse, uniform and ultrasmall chromium oxide (Cr2O3) nanocrystals (NCs). Transmission electron microscope (TEM) image of as-prepared Cr2O3 NCs shows the spherical shape with a uniform size of ∼4.5 nm. The oxidation state of chromium ion has confirmed by absorption as well as electron paramagnetic resonance (EPR) spectroscopy. Magnetic properties of as-synthesized NCs show low-temperature antiferromagnetic (AFM) exchange with Currie-Weiss (C-W) temperature ϴ = −160 K. Further, nearest neighbour exchange coupling constant JNN has found to be −16 K (Here K is Boltzmann constant) for Cr2O3 NCs by considering the nearest neighbours (Z) is 4.

In this paper, Ni–Cu nanoparticles with diameter ~ 5–7 nm decorated onto the surface molybdenum disulfide/reduced graphene oxide (Ni–Cu@MoS2/rGO) were prepared using a simple two-step hydrothermal route. The electromagnetic wave absorbing, and microwave shielding properties of as-prepared MoS2 nanosheet and Ni–Cu@MoS2/rGO composite were tested in the X-band (8.0–12.0 GHz) frequency range. The maximum total shielding effectiveness (SET) of the Ni–Cu@MoS2/rGO composite is found to be ~ 33.47 dB, whereas SET of the MoS2 nanosheet has around ~ 7.17 dB for the same thickness 1.8 mm. Therefore, decoration of Ni–Cu onto the surface of MoS2 sandwiched rGO nanosheet enhances its dielectric loss and microwave shielding ability with lightweight, high specific surface area, high electrical conductivity, higher chemical, and mechanical stability. Enhanced interfacial polarization, multiple internal reflection loss, dipole polarization, multi-scattering loss, and conductance loss is beneficial for high-performance microwave shielding materials. First time report Ni–Cu@MoS2/rGO composite is considered as good microwave shielding materials and used for techno-commercial applications.

In this paper, authors report a facile synthesis of reduced graphene oxide-ZnO (rGO-ZnO) nanocomposite via the solvothermal method for excellent electromagnetic interference (EMI) shielding application. Various characterization tools such as Transmission Electron Microscope (TEM), X-ray diffractometer (XRD) and Raman spectroscope have been employed to understand the morphology and crystal structure of rGO-ZnO nanocomposite, which clearly reveals ZnO nanoparticles (with average size ∼25 nm) to get dispersed well over the surface of rGO. These ZnO nanoparticles, assembled over the top of rGO sheets, form an rGO-ZnO heterostructure with enhanced polarization centers. ZnO nanostructures not only prevent rGO nanosheets to agglomerate but also to contribute significantly in improved scattering, dielectric loss, and impedance matching properties of heterostructure nanocomposite. EMI shielding properties of rGO-ZnO nanocomposites have been evaluated in X-band frequency range (8–12 GHz) and indicate clearly that rGO-ZnO (SET ∼ 38 dB) nanocomposite exhibits an excellent shielding property as compared to its constituent components (SET ∼ 22 dB for rGO and ∼4 dB for ZnO nanoparticles, respectively). Variation of real and imaginary parts of permittivity and permeability provides the idea of attenuating rGO-ZnO nanocomposite. Moreover, it's dielectric and magnetic loss parameters demonstrate the impedance matching characteristics of the rGO-ZnO nanocomposite.

Gallbladder carcinoma is a highly lethal but relatively rare neoplasm of the digestive tract. p53 mutations are one of the most frequent genetic alterations in human cancers and are thought to play a role in pathogenesis of several malignancies. Kras oncogene is responsible for high frequency recognized as an early event in pancreatic and colonic carcinogenesis. We investigated the genetic change of p53, Kras and histopathological changes in gallbladder cancer tissue samples. P53 mutation was seen in the axons 5, 6, 7 and 8 of p53 gene and Kras codon 12 mutations in 25 operative specimens of gallbladder carcinoma. The hispathology observations and polymerase chain reaction-based techniques of these patients were used for point mutations study in p53 and in codon 12 of Kras gene. Mutations of p53 analyzed from exons 5 to 8 using the method of PCR-SSCP were 44%, PCR-RFLP was carried out, and incidence of mutation in codon 12 of Kras was 48% in the adenocarcinoma patients. There was a significant correlation between presence of gall stone, histopathological type, cellular differentiation, grade, lymphovascular invasion, perineural invasion, lymph node invasion, involvement of cystic duct end margin, liver invasion, omental tissue invasion, and T.N.M. staging. Curative surgical resection remains the only effective approach for treatment of GBC. Studies with large number of cases with latest application, next-generation sequencing, DNA microarray, transcriptome analysis, and real-time PCR would help in exploring more targets and better classification of these cancers at genetic level.

Magnetic CoFe2O4 nanoparticles decorated onto the surface of a MoS2-reduced graphene oxide (MoS2-rGO/CoFe2O4) nanocomposite were synthesized by a simple two-step hydrothermal method. The electromagnetic (EM) wave absorption performance and electromagnetic interference (EMI) shielding effectiveness of the materials were examined in the frequency range of 8.0–12.0 GHz (X-band). The MoS2-rGO/CoFe2O4 nanocomposite was characterized by various tools such as X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. High-resolution transmission electron microscopy results confirmed the decoration of magnetic nanoparticles onto the surface of the MoS2-rGO nanocomposite with a diameter of 8–12 nm. The multiple interfacial polarization, moderate impedance matching, and defect dipole polarization improve the dielectric and magnetic loss of the materials, which leads to strong attenuation loss ability of incident EM energy within the shield. The pure MoS2-rGO nanocomposite represents total shielding effectiveness (SET ∼16.52 dB), while the MoS2-rGO/CoFe2O4 nanocomposite exhibits total shielding effectiveness (SET ∼19.26 dB) over the entire frequency range. It may be explained that the magnetic nanoparticles (CoFe2O4) serve as excellent conductive and magnetic fillers with a large surface area, leading to the migration of charge carriers at multi-interfaces.

Ultrafast transient absorption (TA) spectroscopy has been carried out to study the charge carrier dynamics of CdSe core and CdSe/V2O5 core/shell quantum dots (QDs). A significant redshift accompanied by broadening in the first excitonic peak was observed in the UV-Vis absorption spectra of the core/shell QDs as the shell thickness increases. This interesting observation is related to a quasi-type-II alignment characterized by the spatial separation of an electron into the core/shell and a hole into the core. The observed optical excitonic spectra have further been used to study the energetics of CdSe and charge separated states with the concept of Marcus theory and confirmed that electron transfer takes place in the Marcus inverted region (). Moreover, the growth kinetics of the CdSe core and CdSe/V2O5 core/shell QDs, studied with TA spectroscopy, exhibits slow electron cooling in core/shell QDs because of the de-coupling of the electronic wave functions with their hole counterpart. These exciting properties reveal a new paradigm shift from CdSe QDs to CdSe/V2O5 core/shell QDs for highly suitable applications in photovoltaics (PV) and optoelectronic devices.

In this paper, we demonstrate a facile solvothermal synthesis of a vanadium(V) doped MoS2-rGO nanocomposites for highly efficient electrochemical hydrogen evolution reaction (HER) at room temperature. The surface morphology, crystallinity and elemental composition of the as-synthesized material have been thoroughly analyzed. Its fascinating morphology propelled us to investigate the electrochemical performance towards the HER. The results show that it exhibits excellent catalytic activity with a low onset potential of 153 mV versus reversible hydrogen electrode (RHE), a small Tafel slope of 71 mV dec−1, and good stability over 1000 cycles under acidic conditions. The polarization curve after the 1000th cycle suggests there has been a decrement of less than 5% in current density with a minor change in onset potential. The synergistic effects of V-doping at S site in MoS2 NSs leading to multiple active sites and effective electron transport route provided by the conductive rGO contribute to the high activity for the hydrogen evolution reaction. The development of a high-performance catalyst may encourage the effective application of the as-synthesized V-doped MoS2-rGO as a promising electrocatalyst for hydrogen production.

Electromagnetic interference (EMI) pollution has now become a subject of great concern with the rapid development of delicate electronic equipment in commercial, civil, and military operations. There has been a surge in pursuit of light-weight, adaptable, effective, and efficient EMI screening materials in recent years. The present article addresses a simple and sensitive approach to synthesize a core/shell carbon nanotube/MoS

Control over the magnetic interactions in magnetic nanoparticles (MNPs) is a crucial issue to the future development of nanometer-sized integrated “spintronic” applications. Here, we have developed a nanohybrid structure to achieve room temperature ferromagnetism, via a facile, effective, and reproducible solvothermal synthesis method. The plan has been put onto cobalt (Co) NPs, where the growth of Co NPs on the surface of reduced graphene oxide (rGO) nanosheets switches the magnetic interactions from superparamagnetic to ferromagnetic at room temperature. Switching-on ferromagnetism in this nanohybrid may be due to the hybridization between unsaturated 2pz orbitals of graphene and 3d orbitals of Co, which promotes ferromagnetic long-range ordering. The ferromagnetic behavior of Co-rGO nanohybrid makes it excellent material in the field of spintronics, catalysis, and magnetic resonance imaging.

In the field of optoelectronics, all-inorganic CsPbBr

The present article demonstrates the synthesis of the nanocomposite of reduced graphene oxide (rGO) with CdSe and CdSe/V