Studying turbulence in a fluid with background damping.

In this experimental paper, we demonstrate that turbulence can develop in a fluid system with background damping. For that purpose, we analyze dust acoustic waves, self-excited in a fluid complex plasma where the motion of individual microparticles was recorded with a high-speed video camera. We use the Wiener-Khinchin theorem to calculate the kinetic spectrum during different phases of the highly nonlinear periodic wave motion and show that a turbulent cascade develops at the phases of highest particle compression. We demonstrate that the energy cascade occurs despite the presence of a damping force due to the background neutral gas.

Spatial distribution of dust density wave properties in fluid complex plasmas.

Complex plasmas consist of microparticles embedded in a low-temperature plasma and allow investigating various effects by tracing the motion of these microparticles. Dust density waves appear in complex plasmas as self-excited acoustic waves in the microparticle fluid at low neutral gas pressures. Here we show that various properties of these waves depend on the position of the microparticle cloud with respect to the plasma sheath and explain this finding in terms of the underlying ion-drift instability. These results may be helpful in better understanding the propagation of dust density waves in complex plasmas and beyond, for instance, in astrophysical dusty plasmas.

Traumatic bilateral posterior hip dislocation in 10 year old male child.

Traumatic bilateral posterior hip dislocation in skeletally immature patient is reported very less in literature. We report a 10 yr old boy presented to us following farmyard injury with bilateral posterior hip dislocation, which was reduced manually under sedation with uneventful follow-up and complete hip range of motion at 2 year.

Simvastatin local drug delivery in smokers with chronic periodontitis: a randomized controlled clinical trial.

BACKGROUND: Simvastatin (SMV) is a specific competitive inhibitor of 3-hydroxy-2-methyl-glutaryl coenzyme A reductase. Statins have recently been shown to promote bone formation. This study was designed to investigate the effectiveness of SMV 1.2% in an indigenously prepared biodegradable controlled release gel as an adjunct to scaling and root planing (SRP) in the treatment of smokers with chronic periodontitis. METHODS: Forty patients were categorized into two treatment groups: SRP plus SMV 1.2% and SRP plus placebo. Clinical parameters were recorded at baseline and at 3, 6 and 9 months; they included modified sulcus bleeding index (mSBI), probing depth (PD) and clinical attachment level (CAL). At baseline, after 6 months and 9 months, radiologic assessment of intrabony defect (IBD) fill was done using computer-aided software. RESULTS: Mean probing depth reduction and mean clinical attachment level gain was greater in the SMV group than the placebo group at all visits. Furthermore, significantly greater mean percentage of bone fill was found in the SMV group (32.37 ± 10.23%) compared to the placebo (4.18 ± 5.39%). CONCLUSIONS: There was a greater decrease in mSBI and PD and more CAL gain with significant IBD fill at sites treated with SRP plus locally delivered SMV in smokers with chronic periodontitis.

Local drug delivery of 0.5% azithromycin in the treatment of chronic periodontitis among smokers.

BACKGROUND: Along with conventional periodontal surgical therapy, local delivery of antibiotics may provide more effective treatment in smokers by targeting tissue-invasive bacteria. The aim of this randomized, placebo-controlled, double-masked clinical trial was to evaluate the adjunctive effects of subgingivally delivered 0.5% azithromycin (AZM) as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis in smokers. METHODS: Fifty-four patients were randomized and categorized into two treatment groups: Group 1 - 26 subjects who received (SRP) plus placebo gel and Group 2 - 28 subjects who received (SRP) plus 0.5% azithromycin. Clinical parameters were recorded at baseline, 3, 6 and 9 months. They included Plaque Index (PI), modified Sulcus Bleeding Index (mSBI), probing depth (PD) and clinical attachment level (CAL). RESULTS: Azithromycin resulted in significant improvements. A single application of AZM resulted in attachment gain at 9 months of 2.44 ± 0.64 mm as compared to 0.18 ± 0.68 mm for the placebo. Similarly, pocket depth and PI were significantly reduced but no change in the mSBI was noted. CONCLUSIONS: When compared to the placebo, the adjunctive use of 0.5% AZM resulted in significant improvement in clinical outcome in the treatment of chronic periodontitis among smokers.

Comparison of efficacy of three commercially available dentifrices [corrected] on dentinal hypersensitivity: a randomized clinical trial.

BACKGROUND: Dentinal hypersensitivity has been defined as a short, sharp pain arising from exposed dentine as a result of various stimuli such as heat, cold, chemical, or osmotic, that cannot be ascribed to any other pathology. This study was conducted to assess the efficacy of three commercially available toothpastes in the reduction of dentinal hypersensitivity. METHODS: A total of 149 subjects (72 males and 77 females; aged 20 to 60 years) were entered into the study and randomly divided into four groups: Group 1 - toothpaste containing 5% potassium nitrate; Group 2 - toothpaste containing 5% calcium sodium phosphosilicate with fused silica; Group 3 - toothpaste containing 3.85% amine fluoride; and Group 4 - a placebo toothpaste. After sensitivity scores for controlled air stimulus and cold water at baseline were recorded, subjects were given toothpastes and sensitivity scores were measured again at 2 weeks and 6 weeks. RESULTS: All groups showed a reduction in sensitivity scores at 2 weeks and 6 weeks. The calcium sodium phosphosilicate group was found to be significantly better compared to the other groups at the end of 6 weeks. CONCLUSIONS: The calcium sodium phosphosilicate group showed a better reduction in the symptoms of dentinal hypersensitivity.

Photodissociation dynamics of halogenated thiophenes at 235 nm: a resonance enhanced multiphoton ionization-time-of-flight (REMPI-TOF) study.

The photodissociation dynamics of halogen-substituted thiophenes, namely, 2-chlorothiophene and 2-bromo-5-chlorothiophene, has been studied in a supersonic molecular beam around 235 nm, using resonance enhanced multiphoton ionization (REMPI) time-of-flight (TOF) technique, by detecting the nascent state of the primary halogen atoms. A single laser has been used for excitation of halothiophenes, as well as for the REMPI detection of photoproducts, namely, chlorine and bromine atoms, in their spin-orbit states X((2)P(3/2)) and X*((2)P(1/2)). We have determined the translational energy distribution, the recoil anisotropy parameter, ß, and the spin-orbit branching ratio, for chlorine and bromine atom elimination channels. State-specific TOF profiles are converted into kinetic energy distributions, using a least-squares fitting method, taking into account the fragment anisotropies, ß(ι). The TOF profiles for Cl, Cl*, Br, and Br* are found to be independent of laser polarization; i.e., the ß is well characterized by a value of ~0.0, within the experimental uncertainties. For 2-chlorothiophene, we have observed two components for the Cl and only one component for the Cl* atom elimination channel in the translational energy distributions. The average translational energies for the fast and the slow components of the Cl channel are 3.0 ± 1.0 and 1.0 ± 0.5 kcal/mol, respectively. For Cl*, the average translational energy is 3.5 ± 1.0 kcal/mol. For 2-bromo-5-chlorothiophene, we have observed only one component for Cl, Cl*, Br, and Br* in the translational energy distributions. The average translational energies for the Cl and Cl* channels are 3.5 ± 1.0 and 5.0 ± 1.0 kcal/mol, respectively, whereas the average translational energies for the Br and Br* channels are 2.0 ± 1.0 and 3.5 ± 1.0 kcal/mol, respectively. The energy partitioning into the translational modes is interpreted with the help of various models, such as impulsive and statistical models. The ΔH(f)(298) value for 2-chlorothiophene has been estimated theoretically to be 23.5 kcal/mol.

Clinical and microbiologic effects of commercially available gel and powder containing Acacia arabica on gingivitis.

BACKGROUND: There is a need for an anti-plaque agent that can be used on a daily basis without the side effects of antibacterial chemicals such as chlorhexidine. The present study was designed to evaluate the clinical and microbiologic effects of commercially available gel and powder containing Acacia arabica in subjects with gingivitis. METHODS: One hundred and twenty subjects with chronic generalized gingivitis were selected and randomly divided into four groups: Group 1 - placebo group; Group 2 -Acacia arabica gel group; Group 3 -Acacia arabica powder group; and Group 4 - 1% chlorhexidine gel group. Microbial counts of plaque samples, the gingival index of Loe and Silness and the plaque index were evaluated at baseline, 6 weeks, 12 weeks and 24 weeks. Microbial counts of plaque samples were evaluated at all visits. RESULTS: Acacia arabica gel and powder showed significant clinical improvement in gingival and plaque index scores as compared to a placebo. This improvement was comparable to 1% chlorhexidine gel. The difference between gel and powder with regard to clinical and microbiological parameters was not found to be significant at any time interval. CONCLUSIONS: Both Acacia arabica gel and powder may be useful herbal formulations for chemical plaque control in subjects with gingivitis.

Esthetics with prosthetics in case of maxillary canine transposition: a clinical report.

Transposition is a dental anomaly manifested by a positional interchange of two permanent teeth. The maxillary permanent canine usually transposes with the first premolar and occasionally with the lateral incisor. These are mainly genetically governed and are treated orthodontically if complete segment of tooth is present; in case of missing teeth, participation of cosmetic dentist is must. The present case report describes a situation where left canine to lateral incisor complete transposition was present along with a missing left central incisor. Esthetic rehabilitation of the "smile zone" was the major concern. Scrupulous treatment planning to esthetically contour transposed teeth according to their normal positions, i.e., transposed left canine to lateral incisor and transposed left lateral incisor to canine with replacement of missing tooth, was a challenge.

Silver nanoparticle-loaded PVA/gum acacia hydrogel: synthesis, characterization and antibacterial study.

A simple one-pot method for in situ synthesis of silver nanoparticles (AgNPs), within polyvinyl alcohol/gum acacia (PVA-GA) hydrogel matrix, by gamma radiation-induced cross-linking is reported here. The synthesized hydrogels were characterized by FT-IR, thermogravimetry, dynamic light scattering and inductively coupled mass spectrometry method. The thermal stability was found to be more for the hydrogel loaded with silver nanoparticles and also the percentage silver loading was found to increase with increase in cross-linking density. The influence of gum acacia (GA) concentration on the equilibrium degree of swelling of the synthesized hydrogels, and also on the silver release from hydrogel matrix, was investigated. The size of the silver nanoparticles formed in the hydrogel matrix was in the range of 10-40 nm. The rheological gel point was found to be at 25.34 kGy of radiation dose, for a typical hydrogel synthesized, using 5% GA, 3% PVA and 1mM AgNO3. The antibacterial studies of the synthesized nanosilver-containing hydrogels showed good antibacterial activity against gram-negative bacterium, Escherichia coli.

Acute fibrinous and organising pneumonia presenting as complete lung consolidation.

Acute fibrinous and organising pneumonia (AFOP) is an unusual histopathological pattern of acute lung injury. The clinical manifestations, course and treatment of AFOP have yet to be characterised. All reported cases so far have described bilateral diffuse lung involvement radiologically. We report a case of an adolescent girl who presented with acute hypoxaemic respiratory failure with unilateral complete lung consolidation. She was initially diagnosed with severe community-acquired pneumonia. A computed tomography-guided percutaneous transthoracic trucut biopsy of the left lung revealed the classical histopathological pattern typically observed in AFOP. The patient responded well to treatment involving steroids. The uniqueness of such a presentation in AFOP prompted us to report this case.

Dynamics of Cl (2Pj) atom formation in the photodissociation of fumaryl chloride (ClCO - CH = CH - COCl) at 235 nm: a resonance enhanced multiphoton ionization (REMPI) time-of-flight (TOF) study.

The photodissociation dynamics of fumaryl chloride (ClCO-CH═CH-COCl) has been studied in a supersonic molecular beam around 235 nm using resonance enhanced multiphoton ionization (REMPI) time-of-flight (TOF) technique by detecting the nascent state of the primary chlorine atom. A single laser has been used for excitation of fumaryl chloride and the REMPI detection of chlorine atoms in their spin-orbit states, Cl ((2)P(3/2)) and Cl* ((2)P(1/2)). We have determined the translational energy distribution, the recoil anisotropy parameter, ß, and the spin-orbit branching ratio for chlorine atom elimination channels. To obtain these, measured polarization-dependent and state-specific TOF profiles are converted into kinetic energy distributions, using a least-squares fitting method, taking into account the fragment recoil anisotropies, ß(i). The TOF profiles for both Cl and Cl* are found to be independent of laser polarization; i.e., ß is well characterized by a value of 0.0, within the experimental uncertainties. Two components, namely, the fast and the slow, are observed in the translational energy distribution, P(E(T)), of Cl and Cl* atoms, and assigned to be formed from different potential energy surfaces. The average translational energies for the fast components of the Cl and Cl* channels are 14.9 ± 1.6 and 16.8 ± 1.6 kcal/mol, respectively. Similarly, for the slow components, the average translational energies of the Cl and Cl* channels are 3.4 ± 0.8 and 3.1 ± 0.8 kcal/mol, respectively. The energy partitioning into the translational modes is interpreted with the help of various models, such as impulsive and statistical models. Apart from the chlorine atom elimination channel, molecular hydrogen chloride (HCl) elimination is also observed in the photodissociation process. The HCl product has been detected, using a REMPI scheme in the region of 236-237 nm. The observation of the molecular HCl in the dissociation process highlights the importance of the relaxation process, in which the initially excited parent molecule relaxes to the ground state from where the molecular (HCl) elimination takes place.

Photodissociation dynamics of phosphorus trichloride (PCl3) at 235 nm using resonance enhanced multiphoton ionization (REMPI) with time-of-flight (TOF) mass spectrometry.

The photodissociation dynamics of phosphorus trichloride (PCl(3)) has been studied in a supersonic beam by resonance enhanced multiphoton ionization (REMPI), using time-of-flight (TOF) mass spectrometry. The study is focused on the nascent state of the primary chlorine atom, formed on excitation of the (n, sigma*) transition of the molecule around 235 nm. Dissociation of PCl(3) and the REMPI detection of chlorine atoms are performed, using the same laser around 235 nm. The photofragments, namely, Cl((2)P(3/2)) and Cl*((2)P(1/2)), are probed, using the 2+1 REMPI scheme in the 234-236 nm region. We have determined the photofragment speed distribution, the recoil anisotropy parameter beta, and the spin-orbit branching ratio for chlorine atom elimination channels. Polarization-dependent and state-specific TOF profiles are converted into kinetic energy distributions, using a least-squares fitting method, taking into account the fragment anisotropies. The anisotropy parameters for Cl and Cl* are characterized by values of 0.0 +/- 0.05 and 0.20 +/- 0.05, respectively. Two components, namely, the fast and the slow, are observed in the speed distribution (P(v)) of Cl and Cl* atoms, formed from different potential energy surfaces. The average translational energies for the Cl and Cl* channels for the fast component are 29.7 and 30.6 kcal/mol, respectively. Similarly, for the slow component, the average translational energies for the Cl and Cl* channels are 9.5 and 9.1 kcal/mol, respectively. The energy partitioning into the translational modes is interpreted with the help of an impulsive model, for the fast component, and a statistical model, for the slow component. Apart from the chlorine atom elimination channel, molecular chlorine (Cl(2)) elimination is also observed in the photodissociation of PCl(3). The observation of the molecular chlorine in the dissociation process and the bimodal translational energy distribution of the chlorine atom clearly indicate the existence of a crossover mechanism from the initially prepared state to the ground state.

Deep space infections of neck.

A retrospective study was performed on fourteen cases of deep cervical space infections in the neck admitted for diagnosis and treatment to the ENT Department, during a period of seven years from 1989-1997. Of the fourteen, four patients had Ludwig's angina and of the fourteen, one had a very serious complication resulting in death. Early diagnosis and adequate treatment were of paramount importance. The role of tracheostomy and management of airway in deep cervical space infections of the neck is discussed to gether with bacteriology, antibiotic treatment and surgical management.

Role of parecoxib in pre-emptive analgesia: comparison of the efficacy and safety of pre- and postoperative parecoxib in patients undergoing general surgery.

Management of acute postoperative pain remains sub-optimal despite the availability of multiple analgesics and improved pain management strategies (with nearly 80 % of patients reporting moderate to extreme pain following surgery). To evaluate the role of parecoxib as a pre-emptive analgesic in patients undergoing general surgery, the present study was undertaken. Eighty patients of either sex, aged 18 to 70 years, requiring elective ambulatory general surgery like hernioplasty, appendicectomy, cholecystectomy, etc, were enrolled in this prospective, randomised, assessor-blind, parallel-group, comparative trial. Eligible patients were randomised to receive a single dose of 40 mg of parecoxib IM/IV either 30-45 minutes prior to induction of anesthesia (pre-emptive analgesia) or in the postoperative period when one reported pain or when the effects of anesthesia were worn off (whichever was earlier). The primary measures of efficacy were pain intensity scores measured on a visual analog scale (VAS) and pain relief before and after therapy. Adverse event monitoring, physical examination and changes in laboratory tests, chest x-ray and ECG were used to evaluate safety. A comparison of the pain intensity scores between the two groups revealed that patients treated with parecoxib preoperatively did not complain of pain in the entire postoperative period up to 12 hours. Mild pain (1.05+/-1.36) was reported by patients in this group only at the 24 hours assessment. On the other hand, patients treated with parecoxib in the postoperative period, experienced severe pain at baseline, which declined gradually up to 12 hours. The difference in the pain intensity scores between the two groups was statistically significant at all the time intervals from 0 hour to 24 hours. All the 40 patients (100%) in the pre-operatively treated group reported total pain relief at 12 hours compared to only 22 patients (55%) in the postoperative period. At 24 hours total pain relief was reported by 70% of the patients in the pre-operatively treated group, compared to only 20% (8) patients in the postoperatively treated group. The difference between the two groups was statistically significant in favour of the pre-operatively treated group (p<0.05). Present results suggested that pre-operative administration of parecoxib was more effective than a postoperative use in providing pain relief in postoperative period in patients undergoing elective general surgical procedures. Both the regimens were well tolerated. Based on the above data, it appears that pre-operative dose of parecoxib 40 mg IV/IM is a useful optionfor pre-emptive analgesia in general surgical practice.

Incidental detection of microfilariae in aspirates from Ewing's sarcoma of bone.

Microfilariae have been reported as coincidental findings with various neoplasms. We present a case in which microfilariae were encountered in fine-needle aspiration (FNA) smears from a 10-yr-old boy who presented with a lytic lesion in the diaphysis of the right tibial bone. Stained aspirates from the swelling were composed of a dispersed population of small round cells with scanty to vacuolated cytoplasm. Two sheathed microfilariae with several nuclei and cephalic and caudal clearing were identified. A diagnosis of Ewing's sarcoma with presence of microfilariae of Wuchereria bancrofti was made. The diagnosis of Ewing's sarcoma was confirmed on histopathology.

Dilatación controlada del cuello del útero -un modeloexperimental de dolor visceral / Controlled dilatation of the uterine cervix -an experimental visceral pain model

El dolor originado en el aparato reproductor femenino es un problema clínico de difícil tratamiento. Los modelos experimentales pueden ser una herramienta para estudiar los mecanismos del dolor visceral y obtener así información que ayude a formular nuevas estrategias terapéuticas. El objetivo de este estudio fue desarrollar y evaluar el funcionamiento y la seguridad de un modelo de estimulación nociceptiva del cuello uterino mediante dilatación con balón utilizando la planimetría por impedancia. Se realizaron tres dilataciones consecutivas (repetidas): una dilatación lenta a una velocidad de 1 ml.min-1, una dilatación isovolumétrica y una dilatación rápida a una velocidad de 2 ml.min-1. El modelo se probó primero in vitro con especímenes de histerectomías y después se aplicó a 14 mujeres sanas. Las participantes indicaron la calidad de la percepción y el dolor durante las dilataciones mediante descripciones verbales y el Cuestionario de Dolor de McGill (McGill Pain Questionnaire, MPQ), y la intensidad del dolor con una escala visual analógica electrónica continua. Además, marcaron el lugar donde sentían dolor en un mapa anatómico. El área de la sección transversal (AST) del balón se midió simultáneamente. El procedimiento experimental no fue traumático. Se provocó dolor en todas las participantes, con reflejos en la región hipogástrica y lumbar. Los calificativos utilizados por el MPQ para describir el dolor y las áreas de sensaciones referidas fueron similares a los observados clínicamente en el aborto, el parto y la menstruación. La intensidad del dolor se correlacionó con el AST del balón (r = 0,9, p < 0,001). No se observaron diferencias significativas en los volúmenes del balón (4,2, 3,8 y 3,9 ml) ni el AST (163, 122 y 123 mm2) al alcanzar el umbral de dolor (UD) con las dilataciones repetidas, lo que demuestra la fiabilidad del modelo. Se apreció una correlación significativa entre el volumen y el AST del balón al alcanzar el UD con dilataciones cervicales únicas y repetidas. Durante la distensión isovolumétrica, se constató una mayor intensidad global del dolor con la estimulación cervical más larga que con la más corta. En conclusión, éste es el primer modelo experimental humano de dolor inducido por dilatación del cuello uterino que proporciona un estímulo seguro, controlado y cuantificable que consigue provocar intensidades de dolor fiables. El modelo ofrece, pues, nuevas posibilidades para estudiar el dolor ginecológico y posiblemente permita una mejor caracterización y tratamiento de los síndromes de dolor visceral femenino (AU)

Giant cell tumour of talus with osteosarcomatous transformation in a young male: a case report.

A case of osteosarcomatous transformation in a benign giant cell tumour is described. Spontaneous malignant transformation is rare in a giant cell tumour with only 17 cases reported in the literature till date. In addition, a giant cell tumour arising in the bones of the hands and feet is in itself a rarity. In this instance the lesion presented in the talus of the left ankle in a 13 year old male.