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The synthesis of complex cyclic compounds is extremely challenging for organic chemists. Many transition-metal-salt-mediated cyclizations are reported in literature. Hg(II) salts have been successfully employed in cyclizations to form complex heterocyclic and carbocyclic structures that are impossible to synthesize with other transition metal salts. In this review, we have summarized cyclization reactions that are performed with Hg(II) salts. These salts are also successfully applied in stoichiometric or catalytic amounts to form complex cyclic structures and natural products.

Polysaccharides are abundantly present in fungi and are gaining recognition for their exceptional bioactivities. Hence, the present study aimed to extract intracellular polysaccharides (IPS-1 and IPS-2) from the endophytic Penicillium radiatolobatum and compare their physicochemical and bioactive attributes. The monosaccharide composition analysis revealed the existence of galactose, glucose, and mannose in both the IPS, while a trace amount of xylose was found in IPS-1. Further, FT-IR, 1H NMR, and 13C NMR analysis suggested that the IPS-2 was mainly composed of the β-(1→4)-D-Galactose and β-(1→4)-D-Glucose as the main chain, with the β-(1→6)-D-mannose as branched chains. Compared to IPS-1, the IPS-2 showed higher antioxidant activities with an IC50 value of 108 ± 2.5 μg/mL, 272 ± 4.0 μg/mL, and 760 ± 5.0 μg/mL for ABTS+ scavenging, DPPH radical scavenging, and ferric reducing power, respectively. In addition, the IPS-2 inhibited the viability of prostate cancer (PC-3) cells (IC50; 435 ± 3.0 μg/mL) via apoptosis associated with mitochondrial membrane potential collapse and altered morphological features, which was revealed by cellular staining and flow cytometric analysis. Moreover, no apparent cytotoxic effects were seen in IPS-2-treated (1000 μg/mL) non-cancerous cells (HEK-293 and NIH3T3). Overall, the findings of this study suggest that P. radiatolobatum could be a potent source of polysaccharides with promising antioxidant and anticancer activity.

All-optical devices will play a very significant and crucial role in the modern all-optical network by eliminating the bottleneck of opto-electro-opto- (O-E-O-) conversion. Unfortunately, the conventional logic gates lose information at the output, and the states of the outputs cannot give any credible impressions of the states of the inputs. In this article, at first, the authors have proposed a method of designing an optical three-input-three-output reversible Peres gate. Authors have deployed polarization switching characteristic of Semiconductor Optical Amplifier (SOA) for designing this circuit. The authors have also proposed a method of designing an optical reversible full adder, using two such Peres gates and subsequently a data recovery circuit which can recover the input data of the adder. The authors have chosen frequency encoded data for processing the operation. The proposed scheme has been verified by simulation results.

Polysaccharides are abundantly present in fungi and are gaining recognition for their exceptional bioactivities. Hence, the present study aimed to extract intracellular polysaccharides (IPS-1 and IPS-2) from the endophytic Penicillium radiatolobatum and compare their physicochemical and bioactive attributes. The monosaccharide composition analysis revealed the existence of galactose, glucose, and mannose in both the IPS, while a trace amount of xylose was found in IPS-1. Further, FT-IR, [sup.1]H NMR, and [sup.13]C NMR analysis suggested that the IPS-2 was mainly composed of the β-(1→4)-D-Galactose and β-(1→4)-D-Glucose as the main chain, with the β-(1→6)-D-mannose as branched chains. Compared to IPS-1, the IPS-2 showed higher antioxidant activities with an IC[sub.50] value of 108 ± 2.5 μg/mL, 272 ± 4.0 μg/mL, and 760 ± 5.0 μg/mL for ABTS[sup.+] scavenging, DPPH radical scavenging, and ferric reducing power, respectively. In addition, the IPS-2 inhibited the viability of prostate cancer (PC-3) cells (IC[sub.50]; 435 ± 3.0 μg/mL) via apoptosis associated with mitochondrial membrane potential collapse and altered morphological features, which was revealed by cellular staining and flow cytometric analysis. Moreover, no apparent cytotoxic effects were seen in IPS-2-treated (1000 μg/mL) non-cancerous cells (HEK-293 and NIH3T3). Overall, the findings of this study suggest that P. radiatolobatum could be a potent source of polysaccharides with promising antioxidant and anticancer activity.

Frequency-encoded optical processors based on multivalued logic (MVL) will play a significant role in future all-optical networks. In this work, basic optical logic gates are designed using a modified trinary system, exploiting the switching action of semiconductor optical amplifiers (SOAs) based on the principle of the nonlinear rotation of the polarization of a probe beam in the presence of a pump beam. A control unit capable of performing OR, AND, and XOR logic operations depending on the frequency of the control signal is then developed. Finally, a trinary logic unit is designed to execute 27 different logic operations. The feasibility of these proposals is confirmed by simulation results. In this approach, each trinary bit, i.e., “trit,” is represented by a unique frequency, which in turn helps to address the noise margin problem that arises in intensity-encoded MVL systems. This scheme can therefore play an important role in errorless optical computing and processing.

The replacement of binary logic with the multi-valued logic based (MVL) system in the optical domain might be the way to fulfill the demand of faster data computing with a huge amount of data handling capability. Quaternary logic is one of the most promising MVL. In this article, the authors have proposed a new method of developing optical adder and subtractor based on quaternary logic. The frequency encoding technique is used here for data representation because of its inherent property of constancy during reflection, refraction, and transmission. So that, instead of any fluctuation in intensity, different bits can be processed or communicated without any error and thus, the bit error rate can be minimized which makes the scheme novel one. Polarization switching characteristics of semiconductor optical amplifier are adopted here to develop these basic units. The simulative studies on PSW clarify the optical switching mechanism of it. The optical circuits of quaternary adder and subtractor are also testified with simulation results for different cases and thus the admissibility of the proposed scheme is enhanced.

Pristine Antimony tungstate nanoparticles prepared via a simple hydrothermal process showcase interesting photocatalytic efficiency, degrading Methylene Blue (MB) completely in 180 min under visible light. In this study, the impact on crystalline quality and related optical properties as well as photocatalytic efficiency of antimony tungstate due to temperature variation during hydrothermal synthesis are explored. While X-ray diffraction (XRD) shows the polycrystalline nature of all synthesized samples; however, a systematic increase in crystallite size is revealed by analysing the XRD peak broadening. XRD spectra are further examined by Rietveld analysis showing a change in unit cell volume. Additionally, the overall changes in the corresponding grain size and micro-strain developed in the crystals are determined using the Williamson-Hall plot. Moreover, significant variations in few Raman modes are observed with increasing synthesis temperature. A notable modification in the optical band gap as determined from the absorbance of the UV–Vis spectra is perceived with the change in synthesis temperature within the range of ~ 2.38–2.57 eV. Further, the photoluminescence measurement indicates that the synthesized antimony tungstate is weak luminescent material with a band-to-band emission at ~ 468 nm. Finally, photocatalytic efficiencies of the samples are ascertained to change with the synthesis parameter, estimated by decomposing methylene blue (MB), highest degradation rate constant (k) value is observed as 0.015 min −1 for the sample prepared at 180 °C. While the sample with the highest efficiency is also applied for degrading the Rhodamine B (RhB) and Potassium Dichromate (K 2 Cr 2 O 7 ) under visible light irradiation.

To date, degraded mangrove ecosystem restoration accomplished worldwide primarily aligns towards rehabilitation with monotypic plantations, while ecological restoration principles are rarely followed in these interventions. However, researchers admit that most of these initiatives' success rate is not appreciable often. An integrative framework of ecological restoration for degraded mangroves where site-specific observations could be scientifically rationalized, with co-located reference pristine mangroves as the target ecosystem to achieve is currently distinctively lacking. Through this experimental scale study, we studied the suitability of site-specific strategies to ecologically restore degraded mangrove patches vis-à-vis the conventional mono-species plantations in a highly vulnerable mangrove ecosystem in Indian Sundarbans. This comprehensive restoration framework was trialed in small discrete degraded mangrove patches spanning ~ 65 ha. Site-specific key restoration components applied are statistically validated through RDA analyses and Bayesian t-tests. 25 quantifiable metrics evaluate the restoration success of a ~ 3 ha degraded mangrove patch with Ridgeline distribution, Kolmogorov–Smirnov (K-S) tests, and Mahalanobis Distance (D 2 ) measure to prove the site’s near-equivalence to pristine reference in multiple ecosystem attributes. This restoration intervention irrevocably establishes the greater potential of this framework in the recovery of ecosystem functions and self-sustenance compared to that of predominant monoculture practices for vulnerable mangroves.

Introduction- Body's musculoskeletal system depends on vitamin D, and a lack of it is a widespread health issue worldwide. In terms of reduced quality of life, diminished productivity, and the expense of diagnosis and treatment, low back pain (LBP)and radiculopathy in lumbar degenerative disease is a significant health issue. The present study was conducted to investigate the relationship between vitamin D level and correlation with lowback pain and radiculopathy in lumbar degenerative disease in a medical college of Eastern India. Material and methods- The institution based descriptive observational cross-sectional study was conducted at Department of Neurosurgery, NRS Medical College and Hospital, Kolkata for a study period of one year. Complete history was taken and physical examination was done. Values of serum Vitamin D level and VAS was examined. Results were analysed using SPSS version 25.0. Results- Out of all the 150 patients selected 120 (80%) had vitamin D insufficiency (group A) and 30 (20%) had vitamin D sufficiency. No significant relation was found w.r.t. age, gender, BMI, education, occupation and marital status. The mean±SD value of vitamin D in group A was 15.48±3.12 and in group B was 38.79±6.2 and on comparison results were statistically significant with p value <0.001. The mean±SD value of VAS among low back pain in group A was 5.67±2.67 and in group B was 4.35±1.23, on comparison results were statistically significant with p value <0.001. The mean±SD value of VAS in patients of radiculopathy in group A was 5.23±2.51 and in group B was 4.13±1.04, on comparison results were statistically significant with p value <0.001. Negative correlation (-0.556; -0.558) was found between pain score and vitamin D level with statistically significant association (p<0.001) among low back pain and radiculopathy patients. Conclusion –Significant association was found between vitamin D insufficiency and pain scores of LDD. Most patients of LDD had vitamin d insufficiency in our study. So vitamin D insufficiency can be one of the risk factor for development of LDD. So widespread screening of vitamin D level should be done in all patients of LDD so that we can treat vitamin d insufficiency if present along with other treatment of LDD for overall better management.