Evaluation of changes in tongue pressure with twin-block appliance therapy in growing Class II Div 1 malocclusion. An in vivo study.

INTRODUCTION: Twin-block appliance therapy in patients with Class II Div 1 malocclusion positions the mandible anteroinferior leading to possible alterations in tongue pressure, tongue length, and the oropharynx. OBJECTIVES: To evaluate the changes in tongue pressure, tongue length and dimension of the pharyngeal airway in Class II Division 1 subjects before and after twin-block therapy. MATERIALS AND METHODS: Twenty-four subjects were selected, in the range of 10-14 years (mean-12 years). The tongue pressure was recorded at three regions with sensors placed at the incisive papilla and bilaterally at the molar region of the palate for four minutes. The root mean square (RMS) values were recorded and used for further analysis. Evaluation of tongue length and pharyngeal airway dimension was done using a lateral cephalogram. All the measurements were done before and after twin-block appliance therapy. The paired t-test was performed to compare the changes. RESULTS: Resting tongue pressures decreased from pre-treatment levels to post-treatment at all three regions. Change in ANB angle was found to have a significant negative correlation with tongue length, and pharyngeal airway dimension, a significant positive correlation with pressure at incisive papilla and left molar region and no correlation at right molar region. CONCLUSION: There was a decrease in resting tongue pressure as the malocclusion was corrected from Class II to Class I. Hence, this decrease in pressure could be a contributory factor in the maintenance of the dental equilibrium as lighter forces exist in the oral cavity.

Molecular characterization of Mycobacterium tuberculosis through MPT64 gene polymorphism using next-generation sequencing technology.

Aim: To characterize and analyze polymorphism of the MPT64 gene and evaluate AgMPT64-based immunochromatographic assay (ICA) specificity associated with polymorphism. Materials & methods: A total of 1449 suspected samples were tested for tuberculosis (TB), and the MPT64/rv1980c gene was sequenced using next-generation sequencing for polymorphism analysis. Results: Of the TB-positive individuals, 200 (13.80%), 186 (12.84%) and 129 (8.90%) were positive using the liquid culture, GeneXpert and fluorescence microscopy assays, respectively. Liquid culture medium-based samples were confirmed using ICA, in which 193 (96.5%) were positive while seven (3.5%) were negative. Out of 14 sequenced samples, seven were positive and seven negative; 13 were identical to the reference and just one (ICA positive) showed a C477A point mutation (F159L). Conclusion: The results indicate that AgMPT64 can be considered as a potent vaccine candidate.

Design and evaluation of a feed handle for a bench drilling machine.

BACKGROUND: Despite extensive industrial use, no major modifications to the bench drilling machine, with respect to ease of operation, have been undertaken. OBJECTIVE: The objectives of the study were to design a new feed handle (NFH) to perform the drilling task on a bench drilling machine and evaluate the existing (EFH) and new feed handles on the basis of performance measures like drilling productivity in terms of metal removal rate (MRR) and worker performance in terms of perceived discomfort score (PDS). METHODS: Participants performed the drilling task on a steel block for three different working durations at two drilling speeds. RESULTS: ANOVA analysis carried out for the MRR data showed that drilling speed had a statistically significant effect on the task performance of the operator for both handles. However, the task duration was found to be statistically significant only for the EFH. The ANOVA results obtained on the PDS data showed that the task duration and drilling speed had a statistically significant effect on the task performance of the operator for both systems. CONCLUSIONS: The MRR obtained was higher when the drilling task was carried out using NFH. An appreciable decrease in PDS was also observed using the proposed system.

CRISPR/Cas9: Nature's gift to prokaryotes and an auspicious tool in genome editing.

Clustered regularly interspaced short palindromic repeats (CRISPR) is a family of DNA direct repeats found in many prokaryotic genomes. It was discovered in bacteria as their (adaptive) immune system against invading viruses. Cas9 is an endonuclease enzyme linked with the CRISPR system in bacteria. Bacteria use the Cas9 enzyme to chop viral DNA sequences by unwinding it and then finding the complementary base pairs to the guide RNA. CRISPR/Cas9 is a modern and powerful molecular biology approach that is widely used in genome engineering (to activate/repress gene expression). It can be used in vivo to cause targeted genome modifications with better efficiency as compared to meganucleases, zinc-finger nucleases and transcription activator-like effector nucleases. CRISPR/Cas9 is a simple, reliable, and rapid method for causing gene alterations that open new horizons of gene editing in a variety of living organisms, including humans, for the treatment of several diseases. In this short review, we explored the basic mechanisms underlying its working principles along with some of its current applications in a number of diverse fields.

Comparative analysis of the methods used for finding surface energy to investigate protein interaction behavior on chromatographic supports.

Hydrophobic interaction chromatography, an important and effective purification strategy, is generally used for the purification of variety of biomolecules. A basic understanding of the protein interaction behavior is required to effectively separate these biomolecules. A colloidal type extended Derjaguin, Landau, Verwey, and Overbeek calculations were utilized to study the interactions behavior of model proteins to commercially available hydrophobic chromatographic materials that is, Toyopearl Phenyl 650C and Toyopearl Butyl 650C. Physicochemical properties of selected model proteins were achieved by contact angle and zeta potential measurements. The contact angle of chromatographic materials used was achieved through sessile drop method on disrupted beads and capillary penetration method (CPM) on intact beads. The surface properties were further used to calculate the interactions of the proteins to chromatographic supports. The calculated secondary energy minimum of the proteins with the chromatographic materials (from the contact angle values determined through both methods can be correlated with the retention volumes from the real chromatography. The secondary energy minimum values are higher for each protein to the chromatographic materials calculated from the inputs derived through sessile drop method compared to CPM. For instance, immunoglobulin G has secondary energy minimum value of 0.17 kT compared to 0.11 kT, obtained through sessile drop method and CPM, respectively. Average relative values of the energy minimum calculated for all proteins are as 1.51 kT and 1.29 kT for Toyopearl Butyl 650C and Toyopearl Phenyl 650C, respectively, as a conversion factor for estimation of secondary energy minimum for both methods.

Zika virus: what we need to know?

Zika virus is one of the emerging viruses and is of significant threat to human health globally. It is a mosquito borne flavivirus similar to dengue, yellow fever, and West Nile viruses. It was reported about 5 decades ago and then it spreads to different parts of the world. Large outbreaks were reported on Yap Islands in 2007. Now it has gained wide attention globally by health communities. Major vector for virus transmission is Aedes aegypti mosquito. ZIKV infection is mostly asymptomatic but it is also responsible to cause mild influenza like illness to serious manifestations. There is no specific anti-viral treatment is available for ZIKV infection. The virus disseminates very fast due to which it possesses a serious threat especially in those areas where there is lack of specific immunity against virus. Little knowledge is available on its transmission and pathogenicity. Although virus was discovered years ago but its genomic structure is not clearly understood yet. In this review we focus on the current knowledge of epidemiology of ZIKV, its transmission, its structural biology, different aspects of diagnosis and diagnostic challenges as well as highlighted appropriates antiviral drugs and vaccines regarding treatment.

Virus-Templated Near-Amorphous Iron Oxide Nanotubes.

We present a simple synthesis of iron oxide nanotubes, grown under very mild conditions from a solution containing Fe(II) and Fe(III), on rod-shaped tobacco mosaic virus templates. Their well-defined shape and surface chemistry suggest that these robust bionanoparticles are a versatile platform for synthesis of small, thin mineral tubes, which was achieved efficiently. Various characterization tools were used to explore the iron oxide in detail: Electron microscopy (SEM, TEM), magnetometry (SQUID-VSM), diffraction (XRD, TEM-SAED), electron spectroscopies (EELS, EDX, XPS), and X-ray absorption (XANES with EXAFS analysis). They allowed determination of the structure, crystallinity, magnetic properties, and composition of the tubes. The protein surface of the viral templates was crucial to nucleate iron oxide, exhibiting analogies to biomineralization in natural compartments such as ferritin cages.

pH control of the electrostatic binding of gold and iron oxide nanoparticles to tobacco mosaic virus.

We report the binding of nanoparticles (NPs) to wild type (unmodified) tobacco mosaic virus (TMV). The viruses are simply mixed with citrate-coated, negatively charged gold and iron oxide nanoparticles (IONPs) in acidic solution. This results in TMV decorated along its whole length by the respective particles. Such a decoration usually requires chemical modification or mutation of TMV (e.g., cysteine residues), but here we simply reduce TMV's natural negative charge by protonation. The particles are protonated to a much smaller extent. This charge-based mechanism does not operate for neutral particles.

Effect of noise on human performance under variable load in a die casting industry--a case study.

The manual mode of working in industries is very common in the developing and under developed countries. Many industrial processes have generated high levels of noise and causing physiological effects on operators and thus leading to reduced performance. A survey was carried in various die casting industries to determine the levels of noise. It was found that the levels were in the range of 80-100dB(A). The survey also showed that the effects were more pronounced when the task was conducted under varying load conditions. Keeping this in view the problem was formulated to study whether the level of noise and amount of load has a bearing on human performance. For this purpose, experimental investigations in a simulated environment were carried out. Five subjects, all males and having no experience in the trade were selected for the task. The levels of noise under taken were 80, 90 and 100 dB(A) while the levels of load were 150, 200 and 250 N. A pulse oximeter was used to measure the human performance in terms of heart rate. The data was collected and analyzed on the basis of two factor repeated measure type of experimental design. Results of the study indicated that the level of noise and load both were having statistically significant effect on human performance. However, the interaction of level of noise and load was found to be statistically non-significant. The findings of the present work have been discussed in the light of the previous researches carried out on the topic. Suggestions have been made to reduce the levels of noise as per the recommendations of Occupational Safety and Health Association (1990). It is also suggested that instead of hand operated machines, foot operated versions should be used to reduce fatigue.