A Review of Machine Learning Algorithms for Biomedical Applications

As the amount and complexity of biomedical data continue to increase, machine learning methods are becoming a popular tool in creating prediction models for the underlying biomedical processes. Although all machine learning methods aim to fit models to data, the methodologies used can vary greatly and may seem daunting at first. A comprehensive review of various machine learning algorithms per biomedical applications is presented. The key concepts of machine learning are supervised and unsupervised learning, feature selection, and evaluation metrics. Technical insights on the major machine learning methods such as decision trees, random forests, support vector machines, and k-nearest neighbors are analyzed. Next, the dimensionality reduction methods like principal component analysis and t-distributed stochastic neighbor embedding methods, and their applications in biomedical data analysis were reviewed. Moreover, in biomedical applications predominantly feedforward neural networks, convolutional neural networks, and recurrent neural networks are utilized. In addition, the identification of emerging directions in machine learning methodology will serve as a useful reference for individuals involved in biomedical research, clinical practice, and related professions who are interested in understanding and applying machine learning algorithms in their research or practice.

Tribal women empowerment through entrepreneurship: evidence from Mayurbhanj District, Odisha

Introduction

Empowering women in a tribal context through entrepreneurship is an approach for enabling and making them economically and socially viable. This paper aims to highlight entrepreneurship in a specific tribal context and provide insight on some instances or cases relating to women's empowerment. Although there are many initiatives from international organizations and governmental institutions to support women entrepreneurs, especially tribal women, they suffer from isolation as a result of their language and lifestyle differ from the rest of society, which made the growth of their business and ability to compete arduous, and thus affected their ability to make various decisions in their lives. This study examines the pathway to a better understanding of increasing access to entrepreneurship for tribal women in Mayurbhanj district, Odisha.

Methods

The sample size was 111 Santhal tribal women entrepreneurs, and all of them were interviewed using an interview schedule and Focus Group Discussions (FGDs). Two analytical tools were used (a linear regression model to find which dependent variables influence entrepreneurs and the Women's Empowerment Index (WEI) to measure the progress in social and economic opportunities). The respondents was interviewed and asked on the various WEI indicators before and after an entrepreneurship intervention.

Results and discussion

It was observed through the results that the empowerment of women has changed in a positive direction after establishing their work; according to the indicators of the study, the Women's Empowerment Index has changed from 0.61 to 1.26. It was also found that entrepreneurship has a positive and significant impact on women's decision-making within the family, and therefore, it was suggested through research to increase the intervention from the government and related organizations with more initiatives that contribute to the possibility of increasing women's education and their financial ability to open new enterprises.

An intelligent fuzzy-particle swarm optimization supervisory-based control of robot manipulator for industrial welding applications

The propensity of manufacturers to produce goods at affordable cost, with more accuracy, and at a faster rate force them to search for novel solutions, such as deploying robots in place of people in a sector that can accommodate their needs. Welding is one of the most crucial processes in the automotive industry. This process is time-consuming, subject to error, and demands skilled professionals. The robotic application can improve this area of production and quality. Other industries, such as painting and material handling, can also profit from the use of robots. This work describes the fuzzy DC linear servo controller, which functions as a robotic arm actuator. Robots have been widely employed in most productive sectors in recent years, including assembly plates, welding, tasks at higher temperatures, etc. Controlling a robot accurately is a difficult undertaking as a robot is very nonlinear with many joints that are often organized and unstructured. To carry out the effective task, an effective PID control based on fuzzy logic has been employed together with the method of Particle Swarm Optimization (PSO) approach for the estimate of the parameter. This offline technique determines the lowest number of optimal robotic arm control parameters. To verify the controller design with computer simulation, a comparative assessment of controllers is given by means of a fuzzy surveillance controller with PSO which improves the parameter gain to provide a rapid climb, a smaller overflow, no steady condition error signal, and effective torque control of the robot arm.

Vitiligo: Correlation with Cytokine Profiles and its Role in Novel Therapeutic Strategies: A Case-Control Study

Background

The inflammatory and immune factors play a key role in the pathogenesis of vitiligo, and there are very few studies that have investigated the levels of major cytokines produced by T helper (Th) 1, Th2, and Th17 cells. This can enable better understanding of the, pathogenesis, and severity of vitiligo.

Objectives

To evaluate the serum levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-1β, interferon (IFN)-γ, and IL-10 in patients with vitiligo and to correlate them with the disease severity and activity and to compare them with normal healthy controls.

Materials and Methods

A case-control study was conducted with 100 study participants: 50 cases clinically diagnosed as vitiligo and 50 controls. All patients underwent complete evaluation with detailed demographic parameters, history, and physical examination. The severity of the disease was assessed clinically by Vitiligo Area Scoring Index (VASI) and Vitiligo Disease Activity Score (VIDA). Blood investigations performed were IL-6, TNF-α, IL-1β, IFN-γ, and IL-10.

Results

We observed significantly higher levels of serum IFN-γ levels in the patient group when compared with those of the normal controls (P = 0.002) and showed a positive correlation with the activity and severity of the disease with a significant VASI (P = 0.05) and VIDA score (P = < 0.001). The mean serum IL-10 (p < 0.001) in patients with vitiligo was significantly lower than that in the control group. There was no significant difference in the serum level of TNF-α level (P = 0.347), IL-6 (P = 0.365), and IL-1β (P = 0.362) between vitiligo and healthy controls.

Conclusion

This study proved that high serum level of IFN-γ may be a risk factor for vitiligo progression and significantly low levels of IL-10, which has an anti-inflammatory role, suggesting that they could be used as a marker for assessing vitiligo activity and may open the way for further therapeutic approaches for vitiligo.

A Randomized Controlled Study Comparing the Efficacy of Autologous Smashed Follicular Dermal Graft and Epidermal Cell Suspension versus Normal Saline Dressing in the Treatment of Chronic Nonhealing Trophic Ulcers in Patients with Hansen's Disease

Background

Trophic ulcers remain the most common reason for hospitalization in patients with Hansen's disease. With the introduction of new therapeutic regimens, leprosy can now be cured. However, complications of the disease, such as sensory loss, muscle palsy, absorption of extremities, and recurrent ulcers, still lead to substantial morbidity. The management of patients with trophic ulcers and their consequences is difficult, because it is a recurrent and recalcitrant problem.

Aims

To evaluate the efficacy of autologous smashed follicular dermal graft and epidermal cell suspension (ECS) in the treatment of chronic nonhealing trophic ulcers in patients with Hansen's disease and to compare its efficacy with normal saline dressing.

Materials and Methods

A total of 46 chronic nonhealing trophic ulcers were randomized into two groups (23 ulcers in each): Ulcers in Group A were treated with autologous smashed follicular dermal graft and ECS; ulcers in Group B were treated with normal saline dressings. Ulcers were assessed based on the rate of ulcer size reduction at every week till 12 weeks and then once a month till the sixth month.

Results

All 23 (100%) ulcers in Group A had healed within the study period of six months, whereas only 14 (60.9%) ulcers had healed in Group B. Nine (39.1%) ulcers in Group B had not healed even at the end of six months. All 23 (100%) ulcers in Group A had healed within eight weeks, which was statistically significant, P value <0.05.

Conclusion

Trophic ulcers heal faster by autologous smashed follicular dermal graft and ECS, with good results of re-epithelialization of the ulcer bed than by normal saline dressing.

(E)-3-(3-Methylthiophen-2-yl)-1-p-tolylprop-2-en-1-one. Corrigendum

In the paper by Naveen et al. [IUCrData (2017), 2, x170234], there was an error in the name of one of the authors.

Design, crystal structure determination, molecular dynamic simulation and MMGBSA calculations of novel p38-alpha MAPK inhibitors for combating Alzheimer's disease

The hallmark of the Alzheimer's disease (AD) is the accumulation of aggregated, misfolded proteins. The cause for this accumulation is increased production of misfolded proteins and impaired clearance of them. Amyloid aggregation and tau hyperphosphorylation are the two proteinopathies which accomplish deprivation of cell and tissue hemostasis during neuropathological process of the AD, as a result of which progressive neuronal degeneration and the loss of cognitive functions. p38 mitogen-activated protein kinase (p38 MAPK) has been implicated in both the events associated with AD: tau protein phosphorylation and inflammation. p38α MAPK pathway is activated by a dual phosphorylation at Thr180 and Tyr182 residues. Clinical and preclinical evidence implicates the stress related kinase p38α MAPK as a potential neurotherapeutic target. Drug design of p38α MAPK inhibitors is mainly focused on small molecules that compete for Adenosine triphosphate in the catalytic site. Here we have carried out the synthesis of phenyl sulfonamide derivatives Sulfo (I) and Sulfo (II). Crystal structures of Sulfo (I) and Sulfo (II) were solved by direct methods using SHELXS-97. Sulfo (I) and Sulfo (II) have R_int values of 0.0283 and 0.0660, respectively, indicating good quality of crystals and investigated their ability against p38α MAPK. Docking studies revealed that the Sulfo (I) had better binding affinity (-62.24 kcal/mol) as compared to Sulfo (II) and cocrystal having binding affinity of -54.61 kcal/mol and -59.84 kcal/mol, respectively. Molecular dynamics simulation studies of Sulfo (I) and cocrystal of p38α MAPK suggest that during the course of 30 ns simulation run, compound Sulfo (I) attained stability, substantiating the consistency of its binding to p38α MAPK compared to cocrystal. Binding free energy analysis suggests that the compound Sulfo (I) is better than the cocrystal. Thus, this study corroborates the therapeutic potential of synthesized Sulfo (I) in combatting AD.Communicated by Ramaswamy H. Sarma.

Evolutionary engineering of Lactobacillus bulgaricus reduces enzyme usage and enhances conversion of lignocellulosics to D-lactic acid by simultaneous saccharification and fermentation

BACKGROUND

Simultaneous saccharification and fermentation (SSF) of pre-treated lignocellulosics to biofuels and other platform chemicals has long been a promising alternative to separate hydrolysis and fermentation processes. However, the disparity between the optimum conditions (temperature, pH) for fermentation and enzyme hydrolysis leads to execution of the SSF process at sub-optimal conditions, which can affect the rate of hydrolysis and cellulose conversion. The fermentation conditions could be synchronized with hydrolysis optima by carrying out the SSF at a higher temperature, but this would require a thermo-tolerant organism. Economically viable production of platform chemicals from lignocellulosic biomass (LCB) has long been stymied because of the significantly higher cost of hydrolytic enzymes. The major objective of this work is to develop an SSF strategy for D-lactic acid (D-LA) production by a thermo-tolerant organism, in which the enzyme loading could significantly be reduced without compromising on the overall conversion.

RESULTS

A thermo-tolerant strain of Lactobacillus bulgaricus was developed by adaptive laboratory evolution (ALE) which enabled the SSF to be performed at 45 °C with reduced enzyme usage. Despite the reduction of enzyme loading from 15 Filter Paper Unit/g_LCB (FPU/g_LCB) to 5 FPU/g_LCB, we could still achieve ~ 8% higher cellulose to D-LA conversion in batch SSF, in comparison to the conversion by separate enzymatic hydrolysis and fermentation processes at 45 °C and pH 5.5. Extending the batch SSF to SSF with pulse-feeding of 5% pre-treated biomass and 5 FPU/g_LCB, at 12-h intervals (36th-96th h), resulted in a titer of 108 g/L D-LA and 60% conversion of cellulose to D-LA. This is one among the highest reported D-LA titers achieved from LCB.

CONCLUSIONS

We have demonstrated that the SSF strategy, in conjunction with evolutionary engineering, could drastically reduce enzyme requirement and be the way forward for economical production of platform chemicals from lignocellulosics. We have shown that fed-batch SSF processes, designed with multiple pulse-feedings of the pre-treated biomass and enzyme, can be an effective way of enhancing the product concentrations.

Crystal structure and Hirshfeld surface analysis of 2-(4-nitro-phen-yl)-2-oxoethyl picolinate

2-(4-Nitro­phen­yl)-2-oxoethyl picolinate was synthesized under mild conditions. The chemical and mol­ecular structure was confirmed by single-crystal X-ray diffraction studies. The mol­ecules are related by inversion into centrosymmetric dimers via weak C—H⋯O inter­molecular inter­actions, and further strengthened by weak π–π inter­actions. A qu­anti­fication of the inter­molecular contacts in the crystal were estimated using Hirshfeld surface analysis and two-dimensional fingerprint plots.

2-(4-Nitro­phen­yl)-2-oxoethyl picolinate, C₁₄H₁₀N₂O₅, was synthesized under mild conditions. The chemical and mol­ecular structures were confirmed by single-crystal X-ray diffraction analysis. The mol­ecules are linked by inversion into centrosymmetric dimers via weak inter­molecular C—H⋯O inter­actions, forming R₂²(10) ring motifs, and further strengthened by weak π–π inter­actions. Hirshfeld surface analyses, the d_norm surfaces, electrostatic potential and two-dimensional fingerprint (FP) plots were used to verify the contributions of the different inter­molecular inter­actions within the supra­molecular structure. The shape-index surface shows that two sides of the mol­ecules are involved with the same contacts in neighbouring mol­ecules and curvedness plots show flat surface patches that are characteristic of planar stacking.

Crystal structure and Hirshfeld surface analysis of 2-(4-nitro-phen-yl)-2-oxoethyl benzoate

The title com­pound, 2-(4-nitro­phen­yl)-2-oxoethyl benzoate, is relatively planar with the two aromatic rings being inclined to each other by 3.09 (5)°.

The title com­pound, C₁₅H₁₁NO₅, is relatively planar, with the planes of the two aromatic rings being inclined to each other by 3.09 (5)°. In the crystal, mol­ecules are linked by a pair of C—H⋯O hydrogen bonds, forming inversion dimers, which enclose an R₂²(16) ring motif. The dimers are linked by a further pair of C—H⋯O hydrogen-bonds forming ribbons enclosing R₄⁴(26) ring motifs. The ribbons are linked by offset π–π inter­actions [centroid–centroid distances = 3.6754 (6)–3.7519 (6) Å] to form layers parallel to the ac plane. Through Hirshfeld surface analyses, the d_norm surfaces, electrostatic potential and two-dimensional fingerprint (FP) plots were examined to verify the contributions of the different inter­molecular contacts within the supra­molecular structure. The shape-index surface shows that two sides of the mol­ecule are involved with the same contacts in neighbouring mol­ecules, and the curvedness plot shows flat surface patches that are characteristic of planar stacking.

Crystal structure and Hirshfeld surface analysis of 2-(4-nitro-phen-yl)-2-oxoethyl 2-chloro-benzoate

The title compound, C15H10ClNO5, is relatively planar with the two aromatic rings being inclined to each other by 3.56 (11)°. The central -C(=O)-C-O-C(=O)- bridge is slightly twisted, with a C-C-O-C torsion angle of 164.95 (16)°. In the crystal, mol-ecules are linked by C-H⋯O and C-H⋯Cl hydrogen bonds, forming layers parallel to the (101) plane. The layers are linked by a further C-H⋯O hydrogen bond, forming a three-dimensional supra-molecular structure. There are a number of offset π-π inter-actions present between the layers [inter-centroid distances vary from 3.8264 (15) to 3.9775 (14) Å]. Hirshfeld surface analyses, the d norm surfaces, electrostatic potential and two-dimensional fingerprint plots were examined to verify the contributions of the different inter-molecular contacts within the supra-molecular structure. The shape-index surface shows that two sides of the mol-ecule are involved in the same contacts with neighbouring mol-ecules, and the curvedness plot shows flat surface patches that are characteristic of planar stacking.

Membranes for dehydration of alcohols via pervaporation

Alcohols are the essential chemicals used in a variety of pharmaceutical and chemical industries. The extreme purity of alcohols in many of such industrial applications is essential. Though distillation is one of the methods used conventionally to purify alcohols, the method consumes more energy and requires carcinogenic entertainers, making the process environmentally toxic. Alternatively, efforts have been made to focus research efforts on alcohol dehydration by the pervaporation (PV) separation technique using polymeric membranes. The present review is focused on alcohol dehydration using PV separation technique, which is the most efficient and benign method of purifying alcohols that are required in fine chemicals synthesis and developing pharmaceutical formulations. This review will discuss about the latest developments in the area of PV technique used in alcohol dehydration using a variety of novel membranes.

N-[2-(Trifluoromethyl)phenyl]maleamic acid: crystal structure and Hirshfeld surface analysis

The –COOH group of the title compound adopts a syn conformation (O= C—O—H = 0°) unlike the anti conformation observed in related maleamic acids. This is correlated with the formation of carb­oxy­lic acid inversion dimers linked by pairwise O—H⋯O hydrogen bonds in the crystal of the title compound rather than an intra­molecular O—H⋯O hydrogen bond.

The title mol­ecule, C₁₁H₈F₃NO₃, adopts a cis configuration across the –C=C– double bond in the side chain and the dihedral angle between the phenyl ring and side chain is 47.35 (1)°. The –COOH group adopts a syn conformation (O=C—O—H = 0°), unlike the anti conformation observed in related maleamic acids. In the crystal, inversion dimers linked by pairs of O—H⋯O hydrogen bonds are connected via N—H⋯O hydrogen bonds and C—H⋯O inter­actions into (100) sheets, which are cross-linked by another C—H⋯O inter­action to result in a three-dimensional network. The Hirshfeld surface fingerprint plots show that the highest contribution to surface contacts arises from O⋯H/H⋯O contacts (26.5%) followed by H⋯F/F⋯H (23.4%) and H⋯H (17.3%).

Synthesis and X-ray crystal structure analysis of 4-(3,4-dichlorophenyl)-2-(3,4,5-trimethoxy-benzylidene)-3,4-dihydro-naphthalen-1(2H)-one: Sertraline key intermediate analog

The novel bioactive compound 4-(3,4-dichlorophenyl)-2-(3,4,5-trimethoxy-benzylidene)-3,4-dihydro-naphthalen-1(2 H)-one was synthesised in three different methods, namely, conventional, MW irradiation with solvent and MW irradiation without solvent. The synthesised compound was characterised by spectroscopic techniques and finally confirmed by X-ray crystal structure analysis.

Crystal structure and Hirshfeld surface analysis of a bromo-chalcone: (E)-1-(3-bromo-phen-yl)-3-(2,6-di-chloro-phen-yl)prop-2-en-1-one

In the title chalcone derivative, C₁₅H₉Cl₂BrO, the two aryl rings are inclined to each other by 14.49 (17)°, and the olefinic double bond adopts an E configuration. In the crystal, the only short inter­molecular contacts are Cl⋯O contacts [3.173 (3) Å] that link the mol­ecules to form a 2₁ helix propagating along the b-axis direction.

In the title chalcone derivative, C₁₅H₉BrCl₂O, the aryl rings are inclined to each by 14.49 (17)°, and the configuration about the C=C bond is E. There is a short intra­molecular C—H⋯Cl contact present resulting in the formation of an S(6) ring motif. In the crystal, the shortest inter­molecular contacts are Cl⋯O contacts [3.173 (3) Å] that link the mol­ecules to form a 2₁ helix propagating along the b-axis direction. The helices stack up the short crystallographic a axis, and are linked by offset π–π inter­actions [inter­centroid distance = 3.983 (1) Å], forming layers lying parallel to the ab plane. A qu­anti­fication of the inter­molecular contacts in the crystal were estimated using Hirshfeld surface analysis and two-dimensional fingerprint plots.

Crystal structure and Hirshfeld surface analysis of (E)-3-(2-chloro-4-fluoro-phen-yl)-1-(2,5-di-chloro-thio-phen-3-yl)prop-2-en-1-one

In the title chalcone-thio-phene derivative, C13H6Cl3FOS, the aromatic rings are inclined to one another by 12.9 (2)°, and the thio-phene ring is affected by π-conjugation. In the crystal, mol-ecules are linked by C-H⋯F hydrogen bonds, forming an R22(8) ring motif. A Hirshfeld surface analysis was conducted to verify the contribution of the different inter-molecular inter-actions. The shape-index surface clearly shows that the two sides of the mol-ecules are involved in the same contacts with neighbouring mol-ecules and the curvedness plots show flat surface patches characteristic of planar stacking.

Crystal structures of 2-amino-pyridine citric acid salts: C5H7N2+·C6H7O7- and 3C5H7N2+·C6H5O73

2-Amino-pyridine and citric acid mixed in 1:1 and 3:1 ratios in ethanol yielded crystals of two 2-amino-pyridinium citrate salts, viz. C5H7N2+·C6H7O7- (I) (systematic name: 2-amino-pyridin-1-ium 3-carb-oxy-2-carb-oxy-methyl-2-hy-droxy-propano-ate), and 3C5H7N2+·C6H5O73- (II) [systematic name: tris-(2-amino-pyridin-1-ium) 2-hy-droxy-propane-1,2,3-tri-carboxyl-ate]. The supra-molecular synthons present are analysed and their effect upon the crystal packing is presented in the context of crystal engineering. Salt I is formed by the protonation of the pyridine N atom and deprotonation of the central carb-oxy-lic group of citric acid, while in II all three carb-oxy-lic groups of the acid are deprotonated and the charges are compensated for by three 2-amino-pyridinium cations. In both structures, a complex supra-molecular three-dimensional architecture is formed. In I, the supra-molecular aggregation results from Namino-H⋯Oacid, Oacid⋯H-Oacid, Oalcohol-H⋯Oacid, Namino-H⋯Oalcohol, Npy-H⋯Oalcohol and Car-H⋯Oacid inter-actions. The mol-ecular conformation of the citrate ion (CA3-) in II is stabilized by an intra-molecular Oalcohol-H⋯Oacid hydrogen bond that encloses an S(6) ring motif. The complex three-dimensional structure of II features Namino-H⋯Oacid, Npy-H⋯Oacid and several Car-H⋯Oacid hydrogen bonds. In the crystal of I, the common charge-assisted 2-amino-pyridinium-carboxyl-ate heterosynthon exhibited in many 2-amino-pyridinium carboxyl-ates is not observed, instead chains of N-H⋯O hydrogen bonds and hetero O-H⋯O dimers are formed. In the crystal of II, the 2-amino-pyridinium-carboxyl-ate heterosynthon is sustained, while hetero O-H⋯O dimers are not observed. The crystal structures of both salts display a variety of hydrogen bonds as almost all of the hydrogen-bond donors and acceptors present are involved in hydrogen bonding.

Synthesis, spectroscopic and Hirshfeld surface analysis and fluorescence studies of (2E,2'E)-3,3'-(1,4-phenyl-ene)bis-[1-(4-hy-droxy-phen-yl)prop-2-en-1-one] N,N-di-methyl-formamide disolvate

In the bis-chalcone mol-ecule of the title compound, C24H18O4·2C3H7NO, the central benzene and terminal hy-droxy-phenyl rings form a dihedral angle of 14.28 (11)° and the central C=C double bond adopts a trans configuration. In the crystal, the bis-chalcone and solvate mol-ecules are inter-connected via O-H⋯O hydrogen bonds, which were investigated by Hirshfeld surface analysis. Solid-state fluorescence was measured at λex = 4400 Å. The emission wavelength appeared at 5510 Å, which corresponds to yellow light and the solid-state fluorescence quantum yield (Ff) is 0.18.

Toxicity Assessment of Wild Mushrooms from the Western Ghats, India: An in Vitro and Sub-Acute in Vivo Study

Background: Poisoning by different kinds of toxic mushrooms is unfortunately becoming an increasingly important medical problem, evident from the growing number of reports worldwide since the 1950s. Mycetism being a health concern, deserves scientific attention. In this perspective, the present study aims to assess the potential effects of ingesting the selected wild mushrooms from regions of the Western Ghats, India.

Methods: The preliminary cytotoxicity of the selected mushrooms was studied in vitro on the intestinal NCM460 and the Chang's liver cell lines on the basis of cell viability. Further, the hepatotoxicity was assessed by measuring biologically relevant endpoints such as membrane integrity, mitochondrial stress and oxidative status. A 28 day sub-acute toxicity study was carried out by orally administering the mushroom extracts to mice at 250 and 500 mg/kg body weight. The hematological and serum analysis as well as histological examinations were carried out to evaluate their in vivo toxicity. GC-MS analysis of the mushrooms facilitated the identification of their volatile chemical profile.

Result: The in vitro intestinal cytotoxicity exhibited by these wild mushrooms in comparison to the edible mushroom indicated their potential gastrointestinal toxicity. The pathological findings in small intestine on exposure to Chlorophyllum molybdites and Agaricus endoxanthus also validates the speculations about their intestinal toxicity. The toxic insult to the hepatocytes due to Amanita angustilamellata, Entoloma crassum, and Clarkeinda trachodes was predictive of the observed in vivo hepatotoxicity which was also accompanied by renal toxicity at the higher dose of 500 mg/kg bwt.

Conclusion: The potential toxicity exhibited by these representative mushrooms from the wild warrants caution about their consumption. The present work could also have broader implications for global mycetism.

Phosphorescent cyclometalated iridium(iii) complexes: synthesis, photophysics, DNA interaction, cellular internalization, and cytotoxic activity

Phosphorescent cyclometalated quinoline-appended iridium(iii) complexes undergo rapid cellular internalization and accumulate throughout the cell.

Comparative Evaluation of Serum Lipid Profile in Patients with Oral Submucous Fibrosis and Oral Squamous Cell Carcinoma with that of Control Subjects: A Case Control Study

Aim

The aim of the study was to evaluate the serum lipid profile among untreated oral squamous cell carcinoma (OSCC) and oral submucous fibrosis (OSMF) patients.

Materials and Methods

This study was done in three groups of patients - OSMF, OSCC, and control. There are twenty participants in each group. Calorimetric method using semi-autoanalyzer was used for analyzing the lipid levels (cholesterol, triglycerides [TGL], and high-density lipids [HDL]) after collecting 2 ml of fasting blood from these patients. Low-density lipid [LDL] values were obtained by calculator method.

Results

There was a significant decrease in serum lipid levels of patients with OSMF and OSCC.

Conclusion

The decrease in lipid levels in OSMF and OSCC patients is due to its utilization by the cells during the cancer process.

Musculoskeletal Disorders and Mental Health-related Issues as Occupational Hazards among Dental Practitioners in Salem City: A Cross-sectional Study

Background:

Like in any other profession, dental surgeons are also afflicted by many occupational health hazards such as Musculoskeletal disorders (MSD) and mental health related issues.

Aims:

To assess the distribution of MSD and mental health related issues amidst dentists in Salem City according to age, sex and number of working hours per week.

Objectives:

A survey was organized to check the rate of occurrence of these occupational health hazards among dental practitioners in Salem city.

Materials and Methods:

The study was conducted among one hundred and fifty dentists practicing in Salem City in the form of questionnaire. Dentists were asked about any occupational disease that they suffered related to a musculo–skeletal pain and its location whether in the back, upper limbs or lower limbs. In addition to this, dentists were asked about mental stress that they had experienced.

Results:

MSD showed higher rate of prevalence compared to mental health related issues.

Conclusion:

The application of preventive measures is necessary, in view of the high rate of these disorders in the society of dental practitioners.

Crystal structure and Hirshfeld surface analysis of (2E,2'E)-3,3'-(1,4-phenyl-ene)bis-[1-(2,4-di-fluoro-phen-yl)prop-2-en-1-one]

The asymmetric unit of the title compound, C₂₄H₁₄F₄O₂, comprises of one and a half mol-ecules; the half-mol-ecule is completed by crystallographic inversion symmetry. In the crystal, mol-ecules are linked into a three-dimensional network by C-H⋯F and C-H⋯O hydrogen bonds. Some of the C-H⋯F links are unusually short (< 2.20 Å). Hirshfeld surface analyses (d_norm surfaces and two-dimensional fingerprint plots) for the title compound are presented and discussed.

Crystal structure of SAM-dependent methyltransferase from Pyrococcus horikoshii

Methyltransferases (MTs) are enzymes involved in methylation that are needed to perform cellular processes such as biosynthesis, metabolism, gene expression, protein trafficking and signal transduction. The cofactor S-adenosyl-L-methionine (SAM) is used for catalysis by SAM-dependent methyltransferases (SAM-MTs). The crystal structure of Pyrococcus horikoshii SAM-MT was determined to a resolution of 2.1 Å using X-ray diffraction. The monomeric structure consists of a Rossmann-like fold (domain I) and a substrate-binding domain (domain II). The cofactor (SAM) molecule binds at the interface between adjacent subunits, presumably near to the active site(s) of the enzyme. The observed dimeric state might be important for the catalytic function of the enzyme.

An orthorhombic polymorph of (E)-1-(benzo[d][1,3]dioxol-5-yl)-3-(2,3-dichlorophenyl)prop-2-en-1-one

The title compound, C16H10Cl2O3, is almost planar with a dihedral angle of 0.14 (16)° between the benzodioxole ring system and the dichlorobenzene ring that are bridged by the olefinic double bond. The corresponding value reported for the monoclinic polymorph is [5.57 (9)° (Lokeshwariet al.(2017).IUCrData,2, x170103). The carbonyl group lies almost in the plane of the olefinic double bond and is twisted slightly from the benzodioxole ring plane. In the crystal, the molecules are linked by weak C—H...O and C—H...Cl hydrogen bonds, forming a chain propagating along theb-axis direction.

Different supramolecular architectures mediated by different weak interactions in the crystals of three N-aryl-2,5-dimethoxybenzenesulfonamides

The synthesis and evaluation of the pharmacological activities of molecules containing the sulfonamide moiety have attracted interest as these compounds are important pharmacophores. The crystal structures of three closely related N-aryl-2,5-dimethoxybenzenesulfonamides, namely N-(2,3-dichlorophenyl)-2,5-dimethoxybenzenesulfonamide, C₁₄H₁₃Cl₂NO₄S, (I), N-(2,4-dichlorophenyl)-2,5-dimethoxybenzenesulfonamide, C₁₄H₁₃Cl₂NO₄S, (II), and N-(2,4-dimethylphenyl)-2,5-dimethoxybenzenesulfonamide, C₁₆H₁₉NO₄S, (III), are described. The asymmetric unit of (I) consists of two symmetry-independent molecules, while those of (II) and (III) contain one molecule each. The molecular conformations are stabilized by different intramolecular interactions, viz. C-H...O interactions in (I), N-H...Cl and C-H...O interactions in (II), and C-H...O interactions in (III). The crystals of the three compounds display different supramolecular architectures built by various weak intermolecular interactions of the types C-H...O, C-H...Cl, C-H...π(aryl), π(aryl)-π(aryl) and Cl...Cl. A detailed Hirshfeld surface analysis of these compounds has also been conducted in order to understand the relationship between the crystal structures. The d_norm and shape-index surfaces of (I)-(III) support the presence of various intermolecular interactions in the three structures. Analysis of the fingerprint plots reveals that the greatest contribution to the Hirshfeld surfaces is from H...H contacts, followed by H...O/O...H contacts. In addition, comparisons are made with the structures of some related compounds. Putative N-H...O hydrogen bonds are observed in 29 of the 30 reported structures, wherein the N-H...O hydrogen bonds form either C(4) chain motifs or R₂²(8) rings. Further comparison reveals that the characteristics of the N-H...O hydrogen-bond motifs, the presence of other interactions and the resultant supramolecular architecture is largely decided by the position of the substituents on the benzenesulfonyl ring, with the nature and position of the substituents on the aniline ring exerting little effect. On the other hand, the crystal structures of (I)-(III) display several weak interactions other than the common N-H...O hydrogen bonds, resulting in supramolecular architectures varying from one- to three-dimensional depending on the nature and position of the substituents on the aniline ring.

The crystal structure of zwitterionic 2-{[(4-imin-iumyl-3-methyl-1,4-di-hydro-pyridin-1-yl)meth-yl]carbamo-yl}benzoate hemihydrate

The asymmetric unit of the title compound, C₁₅H₁₅N₃O₃·0.5H₂O, comprises two 2-{[(4-iminiumyl-3-methyl-1,4-di-hydro-pyridin-1-yl)meth-yl]carbamo-yl}benzoate zwitterions (A and B) and a water mol-ecule. The dihedral angles between the pyridine and phenyl rings in the zwitterions are 53.69 (10) and 73.56 (11)° in A and B, respectively. In the crystal, mol-ecules are linked by N-H⋯O, O-H⋯O, C-H⋯O and C-H⋯π(ring) hydrogen bonds into a three-dimensional network. The crystal structure also features π-π inter-actions involving the centroids of the pyridine and phenyl rings [centroid-centroid distances = 3.5618 (12) Å in A and 3.8182 (14) Å in B].

Two closely related 2-(benzofuran-2-yl)-2-oxoethyl benzoates: structural differences and C—H...O hydrogen-bonded supramolecular assemblies

The title compounds contain a benzo­furan ring and an ortho-substituted phenyl ring connected by a carbonyl bridge. The mol­ecular conformations of both compounds are similar, but differ in the torsion angles between the ortho-substituted phenyl ring and its adjacent carbonyl group. The crystal structures feature C—H⋯O hydrogen bonds.

The compounds 2-(1-benzo­furan-2-yl)-2-oxoethyl 2-nitro­benzoate, C₁₇H₁₁NO₆ (I), and 2-(1-benzo­furan-2-yl)-2-oxoethyl 2-amino­benzoate, C₁₇H₁₃NO₄ (II), were synthesized under mild conditions. Their mol­ecular structures were characterized by both spectroscopic and single-crystal X-ray diffraction analysis. The mol­ecular conformations of both title compounds are generally similar. However, different ortho-substituted moieties at the phenyl ring of the two compounds cause deviations in the torsion angles between the carbonyl group and the attached phenyl ring. In compound (I), the ortho-nitro­phenyl ring is twisted away from the adjacent carbonyl group whereas in compound (II), the ortho-amino­phenyl ring is almost co-planar with the carbonyl group. In the crystal of compound (I), two C—H⋯O hydrogen bonds link the mol­ecules into chains propagating along the c-axis direction and the chains are inter­digitated, forming sheets parallel to [20-1]. Conversely, pairs of N—H⋯O hydrogen bonds in compound (II) link inversion-related mol­ecules into dimers, which are further extended by C—H⋯O hydrogen bonds into dimer chains. These chains are inter­connected by π–π inter­actions involving the furan rings, forming sheets parallel to the ac plane.