In Vitro Evaluation of marginal adaptation of polyether ether ketone and zirconia copings

Background

Polyether ether ketone (PEEK) has emerged as a new thermoplastic material with potential applications as a restorative material. Aim: This study aimed to evaluate the marginal adaptation of PEEK copings compared to zirconia copings using field emission scanning electron microscopy.

Materials and Methods

A freshly extracted maxillary central incisor was prepared for a full-coverage restoration following standard principles of tooth preparation. The tooth was sent to a laboratory for fabrication of samples using computer-aided design and manufacturing (CAD/CAM). Twenty samples of polyether ether ketone (PEEK) copings (group A) and 20 of zirconia copings were fabricated (group B). The copings were scanned under a field emission scanning electron microscope and measurements were taken at four distinct points. The marginal adaptation over the buccal, lingual, mesial, and distal margins for both groups was evaluated. One-way analysis of variance (ANOVA) and independent t test were applied.

Results

Our findings indicate that PEEK showed better marginal adaptation than zirconia at all measurement points. The mean marginal gap value of the PEEK group was 33.99 ± 8.81 μm and of the zirconia group was 56.21 ± 15.07 μm. On comparing marginal adaptation among the mesial, distal, buccal, and lingual aspects, PEEK showed better adaptation on all four margins, with the best adaptation on the buccal margin that had the lowest mean gap value of 29.27 ± 6.07 μm. The zirconia group adapted best at the distal margin, with a lowest mean gap value of 53.58 ± 15.25 μm (P ≤ 0.05).

Conclusion

PEEK copings had better marginal adaptation and fit compared to zirconia copings. It may have applications as a restorative material in fixed prostheses.

Evolving multidisciplinary treatment of squamous cell carcinoma of the head and neck in India✰

In this article, we highlight the evolution of a multimodal approach in the overall management of squamous cell carcinoma of the head and neck (SCCHN) in India; present advances in technology (newer surgical techniques), novel medical and radiotherapy (RT) approaches; review their roles for an integrated approach for treating SCCHN and discuss the current role of immunotherapy in SCCHN. For locally advanced (LA) SCCHN, the multidisciplinary approach includes surgery followed by RT, with or without chemotherapy (CT) or concurrent chemoradiotherapy. Improved surgical techniques of reconstruction and voice-preservation are being implemented. Advanced forms of high-precision conformal techniques like intensity-modulated radiotherapy are used to deliver highly conformal doses to tumors, sparing the surrounding normal tissue. Compared with RT alone, novel CT regimens and targeted therapeutic agents have the potential to improve locoregional control and survival and reduce treatment-induced toxicities. Several clinical trials have demonstrated efficacy, safety, and quality of life benefits of adding cetuximab to RT regimens in LASCCHN. Studies have also suggested a cetuximab-related laryngeal preservation benefit. At progression, platinum-based CT combined with cetuximab (a monoclonal anti-epidermal growth factor receptor antibody) is the only validated option available as the first-line therapy. Thus, an integrated multidisciplinary approach plays a key role in maximizing patient outcomes, reduction in treatment related morbidities that consequently impact quality of life of survivors.

Femtosecond phase-transition in hard x-ray excited bismuth

The evolution of bismuth crystal structure upon excitation of its A_1g phonon has been intensely studied with short pulse optical lasers. Here we present the first-time observation of a hard x-ray induced ultrafast phase transition in a bismuth single crystal at high intensities (~10¹⁴ W/cm²). The lattice evolution was followed using a recently demonstrated x-ray single-shot probing setup. The time evolution of the (111) Bragg peak intensity showed strong dependence on the excitation fluence. After exposure to a sufficiently intense x-ray pulse, the peak intensity dropped to zero within 300 fs, i.e. faster than one oscillation period of the A_1g mode at room temperature. Our analysis indicates a nonthermal origin of a lattice disordering process, and excludes interpretations based on electron-ion equilibration process, or on thermodynamic heating process leading to plasma formation.

Publisher's Note: Relativistic breather-type solitary waves with linear polarization in cold plasmas [Phys. Rev. E 91, 033102 (2015)]

This corrects the article DOI: 10.1103/PhysRevE.91.033102.

Relativistic breather-type solitary waves with linear polarization in cold plasmas

Linearly polarized solitary waves, arising from the interaction of an intense laser pulse with a plasma, are investigated. Localized structures, in the form of exact numerical nonlinear solutions of the one-dimensional Maxwell-fluid model for a cold plasma with fixed ions, are presented. Unlike stationary circularly polarized solitary waves, the linear polarization gives rise to a breather-type behavior and a periodic exchange of electromagnetic energy and electron kinetic energy at twice the frequency of the wave. A numerical method based on a finite-differences scheme allows us to compute a branch of solutions within the frequency range Ωmin<Ω<ωpe, where ωpe and Ωmin are the electron plasma frequency and the frequency value for which the plasma density vanishes locally, respectively. A detailed description of the spatiotemporal structure of the waves and their main properties as a function of Ω is presented. Small-amplitude oscillations appearing in the tail of the solitary waves, a consequence of the linear polarization and harmonic excitation, are explained with the aid of the Akhiezer-Polovin system. Direct numerical simulations of the Maxwell-fluid model show that these solitary waves propagate without change for a long time.

An evaluation of dental prosthetic status and prosthetic needs among eunuchs (trans genders) residing in bhopal city, madhya pradesh, India: a cross-sectional study

BACKGROUND

Eunuchs are considered as the most vulnerable, frustrated, and insecure community. The accessibility to medical and dental facilities for the eunuchs is nearly nonexistent. Due to these reasons, they might be at a high risk of developing severe dental problems like tooth loss.

AIM

The present cross-sectional study aimed to evaluate the dental prosthetic status and prosthetic needs among eunuchs residing in Bhopal city, Madhya Pradesh, India.

SUBJECTS AND METHODS

On the basis of convenient nonprobability snowball sampling technique, all the self-identified eunuchs residing in the city of Bhopal along with a matched control consisting of cross section of the general population residing in the same locality was examined to evaluate the prosthetic status and prosthetic needs of the population. All the obtained data were entered into a personal computer on Microsoft excel sheet and analyzed using the software; Statistical Package for Social Science version 20. Data comparison was done by applying Chi-square test.

RESULTS

A total of 639 subjects comprised of 207 eunuchs, 218 males and 214 females. Among all participants, 2.8% (18/639) were having prosthesis. The overall prosthetic status among males was 3.2% (7/218) followed by 2.9% (6/207) eunuchs and 2.3% (5/214) females. However, need for multi-unit and combination of one and more unit prosthesis for upper and lower jaws was higher in males compared to females and eunuchs, but the difference was not statistically significant.

CONCLUSION

The findings of this study clearly demonstrate a high unmet need for prosthetic care among the population surveyed.

Modeling relativistic soliton interactions in overdense plasmas: a perturbed nonlinear Schrödinger equation framework

We investigate the dynamics of localized solutions of the relativistic cold-fluid plasma model in the small but finite amplitude limit, for slightly overcritical plasma density. Adopting a multiple scale analysis, we derive a perturbed nonlinear Schrödinger equation that describes the evolution of the envelope of circularly polarized electromagnetic field. Retaining terms up to fifth order in the small perturbation parameter, we derive a self-consistent framework for the description of the plasma response in the presence of localized electromagnetic field. The formalism is applied to standing electromagnetic soliton interactions and the results are validated by simulations of the full cold-fluid model. To lowest order, a cubic nonlinear Schrödinger equation with a focusing nonlinearity is recovered. Classical quasiparticle theory is used to obtain analytical estimates for the collision time and minimum distance of approach between solitons. For larger soliton amplitudes the inclusion of the fifth-order terms is essential for a qualitatively correct description of soliton interactions. The defocusing quintic nonlinearity leads to inelastic soliton collisions, while bound states of solitons do not persist under perturbations in the initial phase or amplitude.

Telaprevir or boceprevir triple therapy in patients with chronic hepatitis C and varying severity of cirrhosis

BACKGROUND

Risks and benefits of protease inhibitor (PI) (telaprevir or boceprevir) triple therapy in hepatitis C virus (HCV)-infected patients with mildly decompensated cirrhosis, including those wait-listed for liver transplantation (LT), are incompletely known.

AIM

To assess virological responses and safety of PI triple therapy in patients with mildly decompensated Child-Pugh (CP) CP ≥6 vs. compensated (CP = 5) cirrhosis.

METHODS

Multicentre cohort of 160 adults with cirrhosis treated with peginterferon/ribavirin (peg-IFN/RBV) plus telaprevir (69%) or boceprevir (31%), comparing outcomes between those with CP = 5 and CP ≥6.

RESULTS

Patients, 47% with CP ≥6 cirrhosis (CP range 6-10), received PI triple therapy for a targeted duration of 48 weeks. The cohort was median age 59 years, 32% female, 59% genotype 1a, 35% previous null/partial responders. Sustained virological response at 12 weeks (SVR12) was achieved by 35% of patients with CP ≥6 vs. 54% of those with CP = 5 (P = 0.02). CP = 5, achievement of rapid virological response and genotype 1b/other, independently predicted SVR12. Compared to those with CP = 5, patients with CP ≥6 had more peg-IFN dose reductions, eltrombopag use, transfusions and hospitalisations to manage adverse events (all P < 0.05). Overall, 67 (42%) discontinued treatment early. Nine wait-listed patients were treated for a median of 97 days (IQR 60-160) prior to liver transplantation and five achieved post-LT SVR.

CONCLUSIONS

In the presence of mild decompensation (Child-Pugh ≥6), SVR12 rates with protease inhibitor triple therapy are significantly reduced and adverse events increased. Thus, treatment with protease inhibitor triple therapy, if judged as necessary, should be undertaken with close monitoring and awareness of the significant risks.

Renal transplantation across ABO barrier

In India, patients without a compatible blood group donor are usually excluded from renal transplantation. For young patients, it is a difficult therapeutic choice to stay on long-term dialysis. We describe the case of a 19-year-old male patient who had blood group O +ve and had no compatible donor in the family. His mother was B +ve and was willing to donate. The patient had an initial anti-B antibody titer of 1:512 and underwent antibody depletion with plasmapheresis (11 sessions) and intravenous immunoglobulin (IVIG) 100 mg/kg after every plasmapheresis. He also received rituximab 500 mg for 3 days prior to transplant and was induced with basiliximab. At the time of transplant, his anti-B titers were <1:8. Post-operatively, he required four sessions of plasmapheresis and IVIG as his titers rebounded to 1:64. The titers then spontaneously subsided to <1:16 and have stayed at the same level for 6 months post-transplant. The patient continues to have normal renal function with a creatinine of 1.4 mg/dl% and has had no episodes of rejection.

Need for a national epilepsy control program

This article briefly outlines the proposed national epilepsy control program. The content of the article is based on four meetings held by invitation of the Ministry of Health. Invitees by ministry – Drs. D. C. Jain, M. Gourie Devi, V. Saxena, S. Jain, P. Satish. Chandra, M. Gupta, K. Bala, V. Puri, K. S. Anand, S. Gulati, S. Johri, P. S. Chandra, M. Behari, K. Radhakrishnan, D. Bachani. Presentations were made by Dr. M. Tripathi.The program will involve all neurologists across the country in teaching and training at state levels and a central monitoring committee.

Knowledge, attitude and practice of epilepsy in Uttarakhand, India

Objectives:

This study was conducted to find out knowledge, attitude and practice (KAP) of epilepsy among 12^th-class students in Uttarakhand state. Secondly data of Uttarakhand was compared with KAP study from other parts of the country.

Materials and Methods:

All 12^th-class students studying in six schools of randomly selected 36 villages in Chakrata block of Dehradun district of Uttarakhand state were provided a printed questionnaire having answer as “yes or no”. This questionnaire used was used previously by various authors and validated for KAP analysis. These filled questionnaires were collected by village health workers and medical officer.

Results:

This study conducted on 219, 12^th-class students revealed that epilepsy was heard by 98%, 74.9% thought epilepsy a mental disease and 4.8% believed that it is contagious. Negative attitude showed as nearly 2/3^rd students stated that epilepsy is hindrance in marriage and occupation. Nearly 41% would use onion or shoe for terminating seizure attack. Ayurvedic treatment was preferred over allopathic drugs.

Conclusions:

Study on 12^th-class students of Uttarakhand revealed poor knowledge, attitude and practice for epilepsy and needs special education program to dispel these misconceptions.

Perioperative outcome of initial 190 cases of robot-assisted laparoscopic radical prostatectomy - A single-center experience

OBJECTIVE

To analyze the perioperative outcome of the first 190 cases of robot-assisted laparoscopic radical prostatectomy performed at our center from July 2006 to December 2010.

MATERIALS AND METHODS

Operative and recovery data for men with localized prostate cancer undergoing robot-assisted radical prostatectomy at our center were reviewed. All surgeries were performed using the 4-arm da Vinci-S surgical robot. Preoperative data included age, body mass index (BMI), prostate specific antigen (PSA) level, prostate weight, biopsy Gleason score and TNM staging, while operative and recovery data included total operative time, estimated blood loss, complications, hospital stay and catheter time. These parameters were evaluated for the safety and efficacy of this procedure in our center.

RESULTS

The mean age of our patients was 65 ± 1.2 years. The mean BMI was 25.20 ± 2.88 and the median PSA was 14.8 ng/ml. Majority of our patients belonged to clinical stage T2 (51.58%). The mean total operative time was 166.44 ± 11.5 min. Six patients required conversion to open procedure and there was one rectal injury. The median estimated blood loss was 302 ± 14.45 ml and the median duration of hospital stay was 4 days. The overall margin positivity rate was 12.63%.

CONCLUSION

Despite our limited robotic surgery experience, our perioperative outcome and complication rate is comparable to most contemporary series. Robot-assisted laparoscopic prostatectomy (RALP) is easy to learn and provides the patient with the benefits of minimally invasive surgery with minimal perioperative morbidity.

Comparison of azathioprine with mycophenolate mofetil in a living donor kidney transplant programme

There are conflicting data regarding the comparative efficacy of mycophenolate mofetil (MMF) versus azathioprine (AZA) as maintenance immunosuppressive agent in kidney transplantation. The data are even less in combination with tacrolimus (TAC) in living donor kidney transplantation. A total of 205 living donor kidney transplants, on TAC-based triple drug immunosuppression were included in the study. A total of 113 patients received AZA and rest 92 were on MMF based protocol. TAC levels were monitored and graft biopsy was done whenever rejection was suspected. The outcomes were evaluated in terms acute rejection (AR) episodes at 1 year, infections, renal function, graft loss, and death between two groups. The study group comprised 163 males (79.5%) and 42 (20.5%) females. The mean age of patients was 42.4±11.8 years in the AZA group and 39.4 ±13.4 in the MMF group (P=0.09). The mean duration of follow-up was 491.7±240.7 and 478.8±334.4 days respectively in the AZA and MMF groups (P=0.75). Thirty-seven of 92 (40.2%) patients in the MMF group and 70/113 (61.9%) patients in the AZA group received IL-2 RAb induction (P=0.002). 32 patients (15.6 %) developed AR within a year. The incidence of AR was similar in patients who received MMF (12/92, 13%) and those who received AZA (20/113, 17.5%), (P=0.36). There was no difference in the incidence of AR in the subgroup of patients who received IL-2 RAb compared to those who did not receive induction in the two groups (5/37 vs. 7/55 in the MMF group and 10/70 vs. 10/43 in the AZA group, P=0.72). The incidence of infections was similar in the two groups (19/92, 20.6% vs. 25/113, 22.1%, P=0.79). Three patients developed CMV disease, of which two were in the MMF group. Graft loss occurred in 7/205 (3.4%) and death in 8/205 (3.9%) patients. Six of eight patients who died had functioning grafts. The rate of graft loss (3/92 vs. 4/113, P=0.97) and death (5/92 vs. 3/113, P=0.27) was similar in two groups. The overall patient survival was 94.5% and death censored graft survival was 97.4%. Cost comparison suggests AZA to be 6-10 times cheaper than MMF. This study suggests that, in tacrolimus-based immunosuppression, azathioprine may be as good as MMF as maintenance immunosuppressive drug in living donor kidney transplantation. It is also a more cost-effective immunosuppression.

Images of the terminal ileum are more convincing than cecal images for verifying the extent of colonoscopy

BACKGROUND AND STUDY AIMS

Independent verification of colonoscopy completion is important for quality assurance. Cecal photographs aimed at showing key landmarks, including the ileocecal valve (ICV) and appendiceal orifice are the currently recommended standard, but are often perceived as unreliable. Images of the terminal ileum demonstrating villi may provide more robust evidence of completion. We sought to prospectively evaluate the ease of routine intubation of the terminal ileum and to compare the effectiveness of terminal ileum and cecal photographs in convincing independent reviewers that total colonoscopy had been accomplished.

PATIENTS AND METHODS

A prospective, observational study evaluated 216 consecutively completed colonoscopies performed in routine clinical practice. Cecal and terminal ileum photographs were evaluated and scored by independent reviewers. Frequency of terminal ileum intubation, time required, and safety parameters were recorded.

RESULTS

The terminal ileum was intubated and photographed in 188/216 (87%) of cases. Median time taken to intubate, or attempt to intubate the terminal ileum was 1 min 24 s, and was achieved without complications or requirement for additional sedation. Terminal ileum images were significantly more likely to be considered convincing than cecal images ( P<0.0001 for all reviewers). There was excellent interobserver agreement amongst the opinion of reviewers regarding terminal ileum photographs (kappa=0.91).

CONCLUSION

Terminal ileum intubation is achievable rapidly and safely in the majority of patients undergoing colonoscopy. Terminal ileum images provide more convincing evidence of complete examination of the colon than cecal images, even when attempts to capture images specifically of the ICV and appendiceal orifice are made.

HIV risk and prevention behaviours, intentions, perceptions and knowledge among youth in Goa, India

In order to examine the association between HIV/AIDS knowledge and perceptions, and risk intentions and behaviours among adolescents in Goa, India, cross-sectional data from 942 youth were collected and assessed. The prevalence rates in the past six months for fighting, smoking, drinking and drug use were 16.5%, 3.8%, 17.8% and 1.1%, respectively; 5.2% acknowledged ever having engaged in sex. Prior risk involvement was significantly correlated with future risk intention (odds ratio [OR]: 9.7-19.7), and those involved in one risk behaviour were more likely to engage in other risk behaviours (OR: 1.3-23.5). The findings suggest the importance of targeted interventions for youth engaging or intending to engage in risk behaviours and universal interventions regarding basic facts and skills for all youth in Goa.

Electrical characterization of self-assembled monolayers of alkyltrichlorosilanes on native oxide of silicon

The octadecyltrichlorosilane (C18), dodecyltrichlorosilane (C12) and octyltrichlorosilane (C8) monolayers have been deposited on the native oxide of silicon by self-assembly technique. The morphology of the monolayers studied by atomic force microscopy revealed an average roughness of approximately 1.0 A. The Fourier Transform Infra Red Spectroscopic measurements revealed the presence of peaks at approximately 2848 and 2915 cm(-1) indicating the formation of densely packed monolayers. The current density versus voltage (J-V) measurements using mercury drop as counter electrode showed tunneling current between 10(-5) to 10(-8) A/cm2 at 1 V indicating the excellent dielectric behaviour of these monolayers. The J-V data were fitted to Simmons theory of tunneling which yielded an effective electron energy barrier height of 1.6 +/- 0.2 eV and the effective mass of electron tunneling through the barrier was found to be 0.3 +/- 0.03 m(e). The tunneling decay factor beta was estimated from the current density values measured as a function of thickness of the monolayer and was found to be 0.28 +/- 0.02 A(-1).

A non-invasive, in vivo technique for monitoring vascular status of glioblastoma during angiogenesis

The growth of solid tumors dependent on the process of angiogenesis in which growth factors secreted by tumor and stromal cells promote endothelial cell proliferation, migration, and maturation. This process generates a tumor-specific vascular supply and enables small or dormant tumors to grow rapidly with exponential increases in tumor volume. Determination of tumor oxygenation at the microvascular level will provide important insight into tumor growth, angiogenesis, necrosis, and therapeutic response, and will facilitate to develop protocols for studying tumor behavior. A non-invasive multi-modality approach based on near infrared spectroscopy (NIRS) technique, namely: Steady State Diffuse Optical Spectroscopy (SSDOS) along with Magnetic Resonance Imaging (MRI) is applied for monitoring the concentration of oxyhemoglobin, deoxyhemoglobin and water within tumor region and for studying the vascular status of tumor and the patho-physiological changes that occur during angiogenesis. Since, the growth of solid tumors depends on the formation of new blood vessels, an association between intramural microvessel density (MVD) and tumor oxygenation is also investigated. The relative decrease in oxygenation value with tumor growth indicates that though blood vessels infiltrate and proliferate the tumor region, a hypoxic trend is clearly present.

CT appearances of hydatid disease at various locations

Hydatid disease has characteristic imaging features on CT, which allow accurate preoperative diagnosis in most cases. However, when it occurs at unusual locations the diagnosis is often difficult, especially as the imaging appearance varies at different sites. In this article we have presented a pictorial review of the CT features of disease due to Echinococcus granulosus at various sites in the human body.

Effect of lectins on the cobalamin-protein binding reactions: implications for the tissue uptake of cobalamin

Plant lectins have been thought to impair nutrient absorption, both by specific and nonspecific interference in the absorptive process. The main objective of this investigation was to study the effect of lectins on the various binding reactions involving cobalamin (cbl)-protein complexes and their receptors, and to identify the rate-limiting step important in maintaining tissue levels of cobalamin. Among the lectins tested in vivo, only concanavalin A (ConA) was able to inhibit the transport of cobalamin to the tissues and caused a 70% to 75% inhibition of [(57)Co] cobalamin transported to the liver and kidney. The inhibition of transport to the tissues was independent of route of administration of cobalamin, whether intragastric or systemic, and was not due to decreased gastrointestinal uptake. When tested in vitro, concanavalin A inhibited the binding of transcobalamin II-cbl to its receptor, but not the binding of cobalamin to intrinsic factor or intrinsic factor-cobalamin complex to the ileal receptor. These results suggest that late events during transcellular transport of cobalamin through the enterocytes is the rate-limiting step determining tissue levels of cobalamin and that ConA inhibits these latter events.

Antithrombin III assay using thrombin in disseminated intravascular coagulation (DIC), other thromboembolic disorders and hepatic diseases

Fifty cases comprising 11 cases of disseminated intravascular coagulation (DIC), 16 cases of venous thromboses and 23 cases of hepatic diseases were studied for AT III levels using clotting assay. Twelve samples were subjected to ATIII estimation by the commercially available synthetic chromogenic assay. Twenty age and sex matched controls were also analysed to find out the reference value for the techniques. Low AT III levels, if present, were correlated with other markers of DIC, viz FDP and D-dimer assays. There was a decrease in the AT III levels in all the three disease categories with a significant difference between the AT III levels of the three disease categories. In DIC, lowest levels were observed which correlated well with FDP and D-dimer levels. There was no significant difference between the average AT III levels measured by both the clotting and synthetic chromogenic assay with the former procedure being relatively inexpensive.