First Search for Nontensorial Gravitational Waves from Known Pulsars

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and [Formula: see text] credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5-[Formula: see text] requires at least three detectors of sensitivity within a factor of [Formula: see text] of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

Perceptions and Attitudes towards Evidence Based Practice among Nurses and Nursing Students in Nepal

Background As the evidence based practice (EBP) movement expands, there is a need for health leaders and educators in each country to assess the extent to which health professional students and practitioners are prepared to locate, evaluate, and apply evidence to guide their practice. Objective The study objective was to explore nurses' and nursing students' perceptions and attitudes towards EBP. Method This was a descriptive cross-sectional survey administered to all 273 nurses and nursing students from Nepal who attended an EBP conference. The survey instrument that was used by Majid in Singapore was adapted for use in this study with permission from the author. Result In total, 121 nurses participated in the study. The majority (93%) of respondents reported that they had no previous training in EBP. The respondents' perceptions of their EBP knowledge and skills were variable, but most of them demonstrated positive attitudes toward EBP. Respondents identified a number of barriers that limit the implementation of EBP in Nepal. The greatest barriers were lack of time and resources, difficulty understanding research articles and translating the findings to practice, and limited autonomy to change practice based on evidence. Conclusion Although respondents had positive attitudes towards EBP, their knowledge and skills were limited and barriers to implementation existed. Nursing faculty can use the findings to guide implementation of EBP into curricula, and nursing administrators and clinicians can use the findings to guide practice to promote EBP.

Effects of transients in LIGO suspensions on searches for gravitational waves

This paper presents an analysis of the transient behavior of the Advanced LIGO (Laser Interferometer Gravitational-wave Observatory) suspensions used to seismically isolate the optics. We have characterized the transients in the longitudinal motion of the quadruple suspensions during Advanced LIGO's first observing run. Propagation of transients between stages is consistent with modeled transfer functions, such that transient motion originating at the top of the suspension chain is significantly reduced in amplitude at the test mass. We find that there are transients seen by the longitudinal motion monitors of quadruple suspensions, but they are not significantly correlated with transient motion above the noise floor in the gravitational wave strain data, and therefore do not present a dominant source of background noise in the searches for transient gravitational wave signals. Using the suspension transfer functions, we compared the transients in a week of gravitational wave strain data with transients from a quadruple suspension. Of the strain transients between 10 and 60 Hz, 84% are loud enough that they would have appeared above the sensor noise in the top stage quadruple suspension monitors if they had originated at that stage at the same frequencies. We find no significant temporal correlation with the suspension transients in that stage, so we can rule out suspension motion originating at the top stage as the cause of those transients. However, only 3.2% of the gravitational wave strain transients are loud enough that they would have been seen by the second stage suspension sensors, and none of them are above the sensor noise levels of the penultimate stage. Therefore, we cannot eliminate the possibility of transient noise in the detectors originating in the intermediate stages of the suspension below the sensing noise.

GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral

On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0×10^{4}  years. We infer the component masses of the binary to be between 0.86 and 2.26  M_{⊙}, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17-1.60  M_{⊙}, with the total mass of the system 2.74_{-0.01}^{+0.04}M_{⊙}. The source was localized within a sky region of 28  deg^{2} (90% probability) and had a luminosity distance of 40_{-14}^{+8}  Mpc, the closest and most precisely localized gravitational-wave signal yet. The association with the γ-ray burst GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. Subsequent identification of transient counterparts across the electromagnetic spectrum in the same location further supports the interpretation of this event as a neutron star merger. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology.

GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence

On August 14, 2017 at 10∶30:43 UTC, the Advanced Virgo detector and the two Advanced LIGO detectors coherently observed a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes, with a false-alarm rate of ≲1 in 27 000 years. The signal was observed with a three-detector network matched-filter signal-to-noise ratio of 18. The inferred masses of the initial black holes are 30.5_{-3.0}^{+5.7}M_{⊙} and 25.3_{-4.2}^{+2.8}M_{⊙} (at the 90% credible level). The luminosity distance of the source is 540_{-210}^{+130}  Mpc, corresponding to a redshift of z=0.11_{-0.04}^{+0.03}. A network of three detectors improves the sky localization of the source, reducing the area of the 90% credible region from 1160   deg^{2} using only the two LIGO detectors to 60  deg^{2} using all three detectors. For the first time, we can test the nature of gravitational-wave polarizations from the antenna response of the LIGO-Virgo network, thus enabling a new class of phenomenological tests of gravity.

GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10∶11:58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2_{-6.0}^{+8.4}M_{⊙} and 19.4_{-5.9}^{+5.3}M_{⊙} (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, a mass-weighted combination of the spin components perpendicular to the orbital plane, χ_{eff}=-0.12_{-0.30}^{+0.21}. This result implies that spin configurations with both component spins positively aligned with the orbital angular momentum are disfavored. The source luminosity distance is 880_{-390}^{+450}  Mpc corresponding to a redshift of z=0.18_{-0.07}^{+0.08}. We constrain the magnitude of modifications to the gravitational-wave dispersion relation and perform null tests of general relativity. Assuming that gravitons are dispersed in vacuum like massive particles, we bound the graviton mass to m_{g}≤7.7×10^{-23}  eV/c^{2}. In all cases, we find that GW170104 is consistent with general relativity.

Melanotrichoblastoma: A Rare Case Report from B. P. Koirala Institute of Health Sciences, Dharan, Nepal

Melanotrichoblastoma is a variant of pigmented trichoblastoma. It shows heavily pigmented epithelial lobules and differentiaion toward the hair bulb. Abundant dendritic melanocytes are found within the tumor masses. These melanocytes show positivity for S100 protein, HMG45/gp 100 and tyrosinase. The case is being reported because of its rarity.A twenty eight year lady presented to Dermatology OPD with a single nodular lesion on the right temporal region since last five years. Punch biopsy was done. Haematoxylin and eosin stained slides were studied and immunohistochemistry analysis was also done.Variably sized epithelial lobules of basaloid cells spanning the entire dermis was noted on H and E stained slides. Some lobules showed pale looking cells- a reminiscent of follicular germinative cells. Intralesional melanocytes with pigmentation were observed. Immunohistochemistry results showed the melanocytes positive for HMB-45 and S100 and the stroma positive for CD 34. Hence, a definitive diagnosis of Melanotrichoblastoma was made.This case is being presented to emphasize the difficulty posed by adnexal tumors in clinical diagnosis due to their clinical similarity with malignant lesion and rarity.Birat Journal of Health Sciences Vol.2/No.1/Issue 2/ Jan - April 2017

First Demonstration of Electrostatic Damping of Parametric Instability at Advanced LIGO

Interferometric gravitational wave detectors operate with high optical power in their arms in order to achieve high shot-noise limited strain sensitivity. A significant limitation to increasing the optical power is the phenomenon of three-mode parametric instabilities, in which the laser field in the arm cavities is scattered into higher-order optical modes by acoustic modes of the cavity mirrors. The optical modes can further drive the acoustic modes via radiation pressure, potentially producing an exponential buildup. One proposed technique to stabilize parametric instability is active damping of acoustic modes. We report here the first demonstration of damping a parametrically unstable mode using active feedback forces on the cavity mirror. A 15 538 Hz mode that grew exponentially with a time constant of 182 sec was damped using electrostatic actuation, with a resulting decay time constant of 23 sec. An average control force of 0.03 nN was required to maintain the acoustic mode at its minimum amplitude.

Perceived Health Promoting Education Needs of Middle-aged Population in Dhulikhel Municipality of Nepal

Background Health promoting education need assessment is of utter importance while conducting health promoting education programs. However little efforts have been put on this by the policy level authorities and there are no studies to assess the perceived health promoting education needs of the middle aged population of Nepal till date. Objective The objective of this study was to assess the perceived health promoting education needs of middle-aged population in Dhulikhel municipality. Method A descriptive cross-sectional study was conducted among 300 respondents using two staged cluster and systematic technique. Face to face interview technique was used for data collection. T-test was used for comparison of dependent variables with independent variables. Result The study revealed that the mean education need score was 66.66±16.09 (in a score of minimum 25 and maximum 125). Cancer prevention was perceived as the topic of highest education need and retirement planning as the topic of least education need. There was statistically significant difference in the mean perceived education need score between male and female (p=0.048), respondents with exposure and non-exposure to health related programs on mass-media (p=0.020) and mental component summary score < 50 and mental component summary scores >=50 (p=0.048). Conclusion This study suggested that the community people have perceived moderate level of health promoting education need. Since cancer prevention was the highest rated topic followed by chronic illness prevention and dementia, it is recommended to focus on these topics while organizing any health promoting education programs in the community.

Pharmacovigilance by World Health Organisation Uppsala Monitoring Center Causality Assessment Algorithm in Medicine Ward of Tertiary Care Hospital of New Delhi

Introduction Pharmacovigilance is not new to India and has in fact been going on since 1998. Adverse drugs reaction (ADRs) are important causes of morbidity and mortality all over the world. They account for approximately 10-20% of all hospitalized patients. The overall incidence of serious ADRs is 6.7% and that of fatal is 0.32%.Objective The objectives of the study was to find the pattern of adverse drug reactions in patients attending medicine ward of a tertiary care center of New Delhi.Methodology A prospective study was conducted from March 2013 to December 2013. On the basis of WHO-UMC causality assessment algorithm, the incidence and pattern of ADRs were assessed from 300 patients of 18 to 70 years of age. The collected data was entered in Microsoft Excel, Common Terminology Criteria for Adverse Events (CTCAE) and analysed by SPSS.Results The incidence of ADRs was found to be 13.67%. More than one ADRs has been reported from some patients. The gender of the patients has no significance in the occurance of ADRs (p=0.194). Highest number of ADRs were found in gastrointestional system followed by central nervous system. Gastrointestional ADRs were must commonly associated with the uses of antimicrobials. The most frequently seen ADRs were diarrhea, gastritis, abdominal pain followed by nausea and vomiting. Decreased level of consciousness (sedation, drowsiness) followed by dizziness and tremors were the frequent ADRs related to the central nervous systems. Based on WHO-UMC causality assessment algorithm, it was observed that a total of 57 ADRs were possible and 2 were probable. No other causality assessment category was observed.Conclusion The ADRs incidence was common even in a tertiary care center. The Gastrointestional and central nervous system disorder were common. The concern of Pharmacovigilance should be initiated.Birat Journal of Health Sciences 2016 1(1): 61-64

Orbital lymphoma in an elderly patient

Lymphomas of the orbit and orbital adnexae are rare tumors, comprising only 1% of all non-Hodgkin’s lymphoma. Lymphomas are the most common primary orbital tumor in adults of age 60 years and older. Here we present a case of 49 year male with left upper lid swelling since 1 year who was diagnosed histopathologically as non-Hodgkin’s lymphoma of orbital region. 

Fine needle aspiration cytology of thyroid and its correlation with serological findings

Background: Thyroid autoimmunity can cause several forms of thyroid disorders i.e. Grave’s disease, Hashimoto’s thyroiditis, atrophic autoimmune thyroiditis, post-partum thyroidits etc. Cytological diagnosis may be sometimes difficult is some cases. In such conditions, cytology along with serological tests aid at reaching a correct diagnosis.Hence, this study was undertaken to evaluate the serum level of anti-TPO antibody with respect to serum concentrations of thyroid hormones and its importance in diagnosing autoimmune thyroiditis.Material and Methods: This study was carried out in the department of pathology from June 2013-May 2014. Patients coming to the department of pathology TUTH, Maharajgunj for FNA of thyroid were included. TFT level was noted and anti TPO antibody level was evaluated by CLIA.Results: Ninety-five thyroid FNAC was included in the study, which comprises of 16.8 % males and 83.2% females with a M: F 1: 4.9. Maximum number of cases was seen in the age range 21-30 years (25.3%), mean age being 40.4years. The cytological diagnosis comprised colloid goiter(43.2%), lymphocytic thyroiditis (25.3%), Hashimoto thyroiditis(18.9%). Out of 42 cases of autoimmune thyroiditis diagnosed cytologically, 16 (38%) were hypothyroid, 4 (9.5%) hyperthyroid, 8 (19%) sub-clinical hypothyroid and 14 (33.5%) were euthyroid. The sensitivity and specificity of positive anti TPO in correctly identifying autoimmune thyroiditis was 85.7% and 79.2% respectively. The positive and negative predictive value for the test was 76.5% and 87.5% respectively.Conclusion: Nodular goitre can harbour a certain per cent of autoimmune thyroiditis and in such cases anti TPO antibody level along with cytodiagnosis appears to be helpful.

Upper Limits on the Stochastic Gravitational-Wave Background from Advanced LIGO's First Observing Run

A wide variety of astrophysical and cosmological sources are expected to contribute to a stochastic gravitational-wave background. Following the observations of GW150914 and GW151226, the rate and mass of coalescing binary black holes appear to be greater than many previous expectations. As a result, the stochastic background from unresolved compact binary coalescences is expected to be particularly loud. We perform a search for the isotropic stochastic gravitational-wave background using data from Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. The data display no evidence of a stochastic gravitational-wave signal. We constrain the dimensionless energy density of gravitational waves to be Ω_{0}<1.7×10^{-7} with 95% confidence, assuming a flat energy density spectrum in the most sensitive part of the LIGO band (20-86 Hz). This is a factor of ∼33 times more sensitive than previous measurements. We also constrain arbitrary power-law spectra. Finally, we investigate the implications of this search for the background of binary black holes using an astrophysical model for the background.

Directional Limits on Persistent Gravitational Waves from Advanced LIGO's First Observing Run

We employ gravitational-wave radiometry to map the stochastic gravitational wave background expected from a variety of contributing mechanisms and test the assumption of isotropy using data from the Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. We also search for persistent gravitational waves from point sources with only minimal assumptions over the 20-1726 Hz frequency band. Finding no evidence of gravitational waves from either point sources or a stochastic background, we set limits at 90% confidence. For broadband point sources, we report upper limits on the gravitational wave energy flux per unit frequency in the range F_{α,Θ}(f)<(0.1-56)×10^{-8}    erg cm^{-2} s^{-1} Hz^{-1}(f/25  Hz)^{α-1} depending on the sky location Θ and the spectral power index α. For extended sources, we report upper limits on the fractional gravitational wave energy density required to close the Universe of Ω(f,Θ)<(0.39-7.6)×10^{-8}  sr^{-1}(f/25  Hz)^{α} depending on Θ and α. Directed searches for narrowband gravitational waves from astrophysically interesting objects (Scorpius X-1, Supernova 1987 A, and the Galactic Center) yield median frequency-dependent limits on strain amplitude of h_{0}<(6.7,5.5,  and  7.0)×10^{-25}, respectively, at the most sensitive detector frequencies between 130-175 Hz. This represents a mean improvement of a factor of 2 across the band compared to previous searches of this kind for these sky locations, considering the different quantities of strain constrained in each case.

Correlation between Preoperative High Resolution Computed Tomography (CT) Findings with Surgical Findings in Chronic Otitis Media (COM) Squamosal Type

Background The exact role of High resolution computed tomography (HRCT) temporal bone in preoperative assessment of Chronic suppurative otitis media atticoantral disease still remains controversial. Objective To evaluate the role of high resolution computed tomography temporal bone in Chronic suppurative otitis media atticoantral disease and to compare preoperative computed tomographic findings with intra-operative findings. Method Prospective, analytical study conducted among 65 patients with chronic suppurative otitis media atticoantral disease in Department of Radiodiagnosis, Kathmandu University Dhulikhel Hospital between January 2015 to July 2016. The operative findings were compared with results of imaging. The parameters of comparison were erosion of ossicles, scutum, facial canal, lateral semicircular canal, sigmoid and tegmen plate along with extension of disease to sinus tympani and facial recess. Sensitivity, specificity, negative predictive value, positive predictive values were calculated. Result High resolution computed tomography temporal bone offered sensitivity (Se) and specificity (Sp) of 100% for visualization of sigmoid and tegmen plate erosion. The performance of HRCT in detecting malleus (Se=100%, Sp=95.23%), incus (Se=100%,Sp=80.48%) and stapes (Se=96.55%, Sp=71.42%) erosion was excellent. It offered precise information about facial canal erosion (Se=100%, Sp=75%), scutum erosion (Se=100%, Sp=96.87%) and extension of disease to facial recess and sinus tympani (Se=83.33%,Sp=100%). high resolution computed tomography showed specificity of 100% for lateral semicircular canal erosion (Sp=100%) but with low sensitivity (Se=53.84%). Conclusion The findings of high resolution computed tomography and intra-operative findings were well comparable except for lateral semicircular canal erosion. high resolution computed tomography temporal bone acts as a road map for surgeon to identify the extent of disease, plan for appropriate procedure that is required and prepare for potential complications that can be encountered during surgery.

Computed Tomographic Evaluation of Craniocerebral Trauma in Dhulikhel Hospital

Background Craniocerebral trauma is common health problem in emergency department of any hospital. CT is commonly indicated to to rule out any significant intracranial abnormalities in these patients, so that timely intervention of the significant intracranial pathologies can be done. Objective The study is done to evaluate CT findings of head injury patients in Dhulikhel Hospital. Method This prospective hospital based study was done in Department of Radiology of Dhulikhel Hospital in the period of January 2015 to December 2015. CT findings of the head trauma patients undergoing CT in the Department of Radiology were reviewed and analysed. Result The study was done in 484 patients, 165 female and 319 male patients. Mean age of the patients was 30.87 ± 19.25 years. Among them 205 patients showed abnormal CT findings, scalp injury being the commonest one, followed by skull fracture. 60 patients showed abnormal intracranial findings. There was significant correlation of skull fracture and abnormal intracranial findings in this study. Conclusion This study provided the normal and abnormal CT findings in head of the craniocerebral trauma patients in Dhulikhel Hospital. Abnormal CT findings were predominantly extra-cranial and were overlapping with intracranial abnormal findings.

A Survey on Oral Health and Practice of Nepalese in Areas Affected by Earthquake in 2015

Background Understanding post-earthquake oral health indicators is essential for developing oral health interventions of the victims. Presumably, due to a geographic difficulty, there has been no investigation to reveal the oral health status of individuals after the Gorkha earthquake in Nepal. Objective The main objective was to determine the oral health and practice of Nepalese affected by earthquake in April-May, 2015. Method The epidemiological cross sectional study was done at 5 different districts (Sindhupalchok, Dadhing, Bhaktapur, Kathmandu and Kavre) of Nepal from September till November, 2015. Altogether 500 subjects aged form 16 to 80 years of age living in the transitional shelters community were included in earthquake-affected areas. Different parameters were studied from past and present medical and dental problems, habits, oral hygiene habits. DMFT, gingival index, periodontal index were studied and correlation was studied among them. Result It shows that 98% of the participants had plaque and 96.4% of the participants had calculus. Mean decayed was 9, mean missing was 4 and mean filling was 1. 22.60% of the participants had score 0, 34.8% had score 1, 34% had score 2 and 8.60% had score 3 of mean gingivitis index. 10% of the participants showed score 0, 36% showed score 1, 35% showed score 2, 10.2% showed score 3 and 8.2% showed score 4 of mean periodontal index. Moreover, significant correlation was observed among DMFT index, gingival index and periodontal index (p<0.001). Conclusion The oral health care practice, oral hygiene habits, nutritional intake of the people have been affected in the earthquake affected areas. It showed high caries index, gingival index and periodontal index in earthquake affected people suggesting further efforts are needed for an oral health improvement. Data from this study may be used as basic information for oral health planning and future steps in oral health care preventive and therapeutic programs.

Determination of Sex from the Foramen Magnum using 3DCT: A Nepalese Study

Background Identification is of utmost importance in any medicolegal investigation with sex determination being one of the principle indicators of identity. Sexing of bones becomes easy when the skeletal remains are complete. However, the problem arises when the bones are fragmented. Many researchers have undertaken several studies in different populations to determine the sex with reasonable accuracy using numerous measurements of the skull including those of the foramen magnum. Objective The present study was aimed to find the sexual dimorphism of the foramen magnum in the Nepalese population by analyzing the antero-posterior length, transverse diameter and area of the foramen magnum. Method The antero-posterior length and transverse diameter of the foramen magnum were measured using three-dimensional computed tomography (3DCT) images of the head in a cohort of 100 Nepalese subjects. Radinsky's and Teixeria's formulae were used to calculate the area of the foramen magnum. Discriminate function analysis was used to analyze sex differences. Result Mean values of antero-posterior length and transverse diameter of the foramen magnum in males were higher than in females. The mean of the area calculated using Radinsky's formula was smaller than that calculated by Teixeira's formula and the areas calculated were higher in males. The measurements of the foramen magnum and the areas calculated showed significant difference (p<0.001) between males and females. Discriminate function analysis for the measurements of the foramen magnum and the areas calculated showed high predictability for both the sexes. Discriminate function analysis showed a maximum predictability of 75%. Conclusion Considering the percent of predictability of sex from the various variables related to the foramen magnum in the Nepalese population, it can be concluded that its restricted applicability in forensic investigations should be constrained to cases of fragmentary skull bases.

The Advanced LIGO photon calibrators

The two interferometers of the Laser Interferometry Gravitational-wave Observatory (LIGO) recently detected gravitational waves from the mergers of binary black hole systems. Accurate calibration of the output of these detectors was crucial for the observation of these events and the extraction of parameters of the sources. The principal tools used to calibrate the responses of the second-generation (Advanced) LIGO detectors to gravitational waves are systems based on radiation pressure and referred to as photon calibrators. These systems, which were completely redesigned for Advanced LIGO, include several significant upgrades that enable them to meet the calibration requirements of second-generation gravitational wave detectors in the new era of gravitational-wave astronomy. We report on the design, implementation, and operation of these Advanced LIGO photon calibrators that are currently providing fiducial displacements on the order of 10^-18m/Hz with accuracy and precision of better than 1%.

Multi-Detector Computed Tomography Evaluation of Normal Appendix

Background Appendix is a blind-ended tubular structure arising from caecum, with variable intraluminal contents and position. Acute appendicitis is one of the common indications for emergency radiological investigation. Objective To assess visualization rate, size and position of normal appendix by Computed Tomography (CT). Method This cross-sectional observational study was done in 198 individuals undergoing abdominal CT without suspicion of acute appendicitis and without any pathology localized within right iliac fossa. Axial and coronal reformatted images of nonenhanced and contrast enhanced CT of abdomen were evaluated for visualization of appendix. Visualized appendices arising from caecum were traced and tip localized. Contents within the appendicular lumen were also evaluated and maximum transverse diameter of appendix measured. The relationship between appendicular diameter, intraluminal content and position with different age groups & gender were also derived. Result Visualization rates of appendix were 90% (93% male and 87% female) in nonenhanced CT and 97% (99.8% male and 95.4% female) in enhanced CT. The mean diameter of the appendix was 6.2 ± 1.16 mm. Most common location of the tip of appendix was pelvic position, followed by retrocaecal position. Most of the appendices showed intraluminal air. Conclusion Multi-Detector Computed Tomography is superior over ultrasonography (USG) in detection of appendix. Modifications of CT protocol reduce limitations of CT over ultrasound in evaluation of appendix. Ultrasound size criteria for appendicitis (>6 mm) is not applicable in CT as normal appendix can measure >6 mm in CT.

Prevalence of Anatomical Variations of the Sinonasal Region and their Relationship with Chronic Rhinosinusitis

Background Precise knowledge of anatomic variations of nose and paranasal sinus complex is essential for achieving best surgical results during endoscopic sinus surgery. Computed tomography is the gold standard investigation for evaluation of paranasal sinuses and adjacent structures. Objective To study prevalence of anatomical variations of nose, paranasal sinuses and osteomeatal complex and to identify a probable association between anatomical variations and chronic rhinosinusitis. Method Prospective, analytical study conducted in 218 patients with Chronic rhinosinusitis in Department of Radiology, Dhulikhel Hospital, Kathmandu University Hospital between January 2015 to January 2016. Volumetric axial CT scan was done in 128 slice CT scanner in 3mm thickness from frontal sinus to floor of maxillary sinus with thin multiplanar reconstruction. Radiological findings were reviewed and obtained data analyzed with SPSS version 16. Pearson chi square test and Pearson correlation coefficient were used for statistical analysis. Result The most common anatomical variation was pneumatized agger nasi cells followed by concha bullosa and deviated nasal septum respectively. Statistical significance were seen between ipsilateral agger nasi cell and frontal sinusitis (p< 0.001), ipsilateral haller cell and concha bullosa with maxillary sinusitis (p<0.001) and onodi cell with sphenoid sinusitis (p<0.001), However, no obvious statistical correlation was noted between deviated nasal septum with ipsilateral maxillary sinusitis. Conclusion Precise knowledge of anatomic variations of the paranasal sinuses is important in chronic rhinosinusitis to prevent possible complications during surgery. Computed tomography is the modality of choice in evaluation of paranasal sinuses and adjacent structures.

Tonsillar tuberculosis : A case report

Tuberculosis of the oral cavity which is an uncommon occurrence can be primary or secondary. In the absence of active pulmonary tuberculosis, isolated tonsillar tuberculosis is rare. Herein, we report two cases of bilateral tonsillar tuberculosis who presented as recurrent sore throat for which tonsillectomy was done. No active primary pulmonary lesion was found in these cases. Histopathological examination revealed caseating epithelioid granulomas with Langhans giant cells. Ziehl Neelson stain for acid fast bacilli was positive in one case. Tonsillar tuberculosis, though a rare entity, should be considered in the clinical differential diagnosis of tonsillar lesions. Histopathological examination with Ziehl Neelson stain should be performed for definite diagnosis.

Characterization of transient noise in Advanced LIGO relevant to gravitational wave signal GW150914

On September 14, 2015, a gravitational wave signal from a coalescing black hole binary system was observed by the Advanced LIGO detectors. This paper describes the transient noise backgrounds used to determine the significance of the event (designated GW150914) and presents the results of investigations into potential correlated or uncorrelated sources of transient noise in the detectors around the time of the event. The detectors were operating nominally at the time of GW150914. We have ruled out environmental influences and non-Gaussian instrument noise at either LIGO detector as the cause of the observed gravitational wave signal.

Imaging in Infertile Female Patients Who Underwent Hysterosalpingography Investigation at Dhulikhel Hospital

Background Fallopian tube and uterine abnormalities are the most common cause of female infertility, accounting for 30% of cases. Hysterosalpingography is the safe, minimal invasive radiographic technique for evaluation of uterine cavity and fallopian tubes defects. The purpose of the study was to assess the various uterine and tubal abnormalities leading to infertility Objective To assess the abnormalities in uterus and fallopian tubes detected on Hysterosalpingography (as causative factors of infertility in a tertiary care centre for proper decision making in treatment. Method This is the prospective cross sectional study done in department of radiology Dhulikhel hospital, Kathmandu University Hospital between January 2015 to January 2016 with complain of infertility. Hysterosalpingography was performed using ionic contrast medium (10-20 ml of 76% urograffin) under digital fluoroscopy. Radiographic films were obtained and analyzed. Demographic data and radiological findings were reviewed and the obtained data analyzed with SPSS version 16. Result Out of the total 100 patient, 75 had primary infertility while 25 had secondary infertility. The age ranged from 19 to 43 years with mean age of 27.75 years. Normal Hysterosalpingography findings were seen in 37% cases. Tubal abnormalities were seen in 34%, uterine abnormalities in 23% and both tubal and uterine abnormalities in 6% patients. The most common tubal abnormality detected on Hysterosalpingography was tubal block 75%. Out of the 30 patients who had tubal block, unilateral block was noted in 76.7% patients whereas bilateral block was noted in 23.3%. Hydrosalphinx was seen in 25% cases with tubal abnormality. Among the 29 cases with various uterine abnormalities, bicornuate uterus 9% was the most common abnormality Conclusion Hysterosalpingography is an easily available radiographic procedure that can demonstrate a wide variety of uterine and tubal abnormalities for the initial assessment of infertility which can avoid unnecessary and sometimes more aggressive procedures.

GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4_{-0.9}^{+0.7}×10^{-22}. The inferred source-frame initial black hole masses are 14.2_{-3.7}^{+8.3}M_{⊙} and 7.5_{-2.3}^{+2.3}M_{⊙}, and the final black hole mass is 20.8_{-1.7}^{+6.1}M_{⊙}. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440_{-190}^{+180}  Mpc corresponding to a redshift of 0.09_{-0.04}^{+0.03}. All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

Properties of the Binary Black Hole Merger GW150914

On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected a gravitational-wave transient (GW150914); we characterize the properties of the source and its parameters. The data around the time of the event were analyzed coherently across the LIGO network using a suite of accurate waveform models that describe gravitational waves from a compact binary system in general relativity. GW150914 was produced by a nearly equal mass binary black hole of masses 36_{-4}^{+5}M_{⊙} and 29_{-4}^{+4}M_{⊙}; for each parameter we report the median value and the range of the 90% credible interval. The dimensionless spin magnitude of the more massive black hole is bound to be <0.7 (at 90% probability). The luminosity distance to the source is 410_{-180}^{+160}  Mpc, corresponding to a redshift 0.09_{-0.04}^{+0.03} assuming standard cosmology. The source location is constrained to an annulus section of 610  deg^{2}, primarily in the southern hemisphere. The binary merges into a black hole of mass 62_{-4}^{+4}M_{⊙} and spin 0.67_{-0.07}^{+0.05}. This black hole is significantly more massive than any other inferred from electromagnetic observations in the stellar-mass regime.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

Tests of General Relativity with GW150914

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13}  km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

Muscular Hamartoma of Intestine Causing Intestinal Obstruction

Hamartomatous causes of small bowel obstructionare uncommon and of them, most are attributed to inflammatory bowel diseases and also certain medications such as NSAIDs. We describe a case of muscular hamartoma in a patient without prior chronic medical condition with brief review of literature.

GW150914: Implications for the Stochastic Gravitational-Wave Background from Binary Black Holes

The LIGO detection of the gravitational wave transient GW150914, from the inspiral and merger of two black holes with masses ≳30M_{⊙}, suggests a population of binary black holes with relatively high mass. This observation implies that the stochastic gravitational-wave background from binary black holes, created from the incoherent superposition of all the merging binaries in the Universe, could be higher than previously expected. Using the properties of GW150914, we estimate the energy density of such a background from binary black holes. In the most sensitive part of the Advanced LIGO and Advanced Virgo band for stochastic backgrounds (near 25 Hz), we predict Ω_{GW}(f=25  Hz)=1.1_{-0.9}^{+2.7}×10^{-9} with 90% confidence. This prediction is robustly demonstrated for a variety of formation scenarios with different parameters. The differences between models are small compared to the statistical uncertainty arising from the currently poorly constrained local coalescence rate. We conclude that this background is potentially measurable by the Advanced LIGO and Advanced Virgo detectors operating at their projected final sensitivity.

GW150914: The Advanced LIGO Detectors in the Era of First Discoveries

Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016. With a strain sensitivity of 10^{-23}/sqrt[Hz] at 100 Hz, the product of observable volume and measurement time exceeded that of all previous runs within the first 16 days of coincident observation. On September 14, 2015, the Advanced LIGO detectors observed a transient gravitational-wave signal determined to be the coalescence of two black holes [B. P. Abbott et al., Phys. Rev. Lett. 116, 061102 (2016)], launching the era of gravitational-wave astronomy. The event, GW150914, was observed with a combined signal-to-noise ratio of 24 in coincidence by the two detectors. Here, we present the main features of the detectors that enabled this observation. At full sensitivity, the Advanced LIGO detectors are designed to deliver another factor of 3 improvement in the signal-to-noise ratio for binary black hole systems similar in mass to GW150914.

Risk Factors for Pneumonia in Children under 5 Years in a Teaching Hospital in Nepal

BACKGROUND

Pneumonia is a leading cause of mortality among children under-five years of age globally. The WHO (2014) has reported that indoor air pollution caused by cooking and heating with biomass fuel, living in crowed homes and parenting smoking are risk factors of pneumonia.

OBJECTIVES

The objective of the study was to identify the risk factors for pneumonia among children under-5 years of age.

METHODS

A case control study was carried out among the mothers having under-5 years children who were admitted in the paediatric ward of Dhulikhel Hospital in 2012/13. A convenience sampling technique was used to select 50 children with pneumonia and 150 children with non-pneumonia diseases matched on age, sex and setting. A semi-structured interview consisting of questions related to risk factors for pneumonia was used to collect data from mothers of both cases and controls.

RESULTS

Sex of the child did not differ by case/control group whereas the children with pneumonia were slightly older with 26% cases and 15% controls older than 3 years of age. Mother's education was similar in both groups as was family income. Living in a household with a chulo with smoke increased the odds of having pneumonia significantly, with the risk almost 4 times greater if the chulo was located within the same building (OR: 3.76, 95% CI: 1.20-11.82, p=0.02). Children who had diarrhea in the past 3 months were protected from pneumonia (OR: 0.38, 95% CI: 0.18- 0.82, p=0.01). An increasing trend of pneumonia was observed among children of tobacco smoking parents with greater risk if both parents smoked; it was, however, not statically significant (OR: 2.21, 95% CI: 0.56-8.82, p=0.26).

CONCLUSION

The present study suggests that two factors related to smoke, presence of a smoky chulo in a household and both parents smoking, are modifiable risk factors related to pneumonia in young children. Reliable longitudinal studies, interventions, and programs to educate parents in prevention are important for reducing mortality and morbidities related to acute respiratory illnesses in Nepal.

Microvessel density in Prostatic Lesions : Relevance to prognosis

Background:  Angiogenesis is required for growth and metastasis of tumor tissue. Quantization of angiogenesis by calculating the microvessel density can be done in histopathology specimens with the help of immunochemistry. In this study we used anti CD 34 antibody to highlight the endothelial cells and thus calculate microvessel density. Most studies have shown a positive correlation of microvessel density with increasing pathological grade and have also shown microvessel density as an independent predictor of cancer progression and survival. The present study was to find out the microvessel density in benign and malignant lesions of prostate and also to correlate the vascularity with increasing grade of cancer.Materials and methods:  Sixty five prostatic biopsies were evaluated for microvessel density using CD34 monoclonal antibody. Comparison was done between BPH and Carcinoma Prostate. MVD was correlated with Gleason’s score, weight of specimen and increasing age of patient. Effect of prostatitis on Microvessel density was studied.Results: Microvessel density was significantly higher in carcinoma prostate than in Benign Prostatic Hyperplasia. There was positive correlation of Microvessel density with increasing Gleason’s score. Microvessel was significantly increased in patients having symptoms for more than a year and also with biopsies revealing prostatitis. However, there was no significant correlation between Microvessel density and weight of specimen or increasing age.Conclusion: Since Microvessel density was found to be significantly higher in Prostatic Carcinoma and it showed positive correlation with Gleason’s score it can be added as one of the indicators for predicting the disease outcome. 

Megakaryocytic alterations in thrombocytopenia: A bone marrow aspiration study

Background: Megakaryocyte morphology plays an important role in thrombopoiesis. A defect in any stage of megakaryocytopoiesis can lead to dysmegakaryocytopoiesis and thrombocytopenia. This study was conducted to understand megakaryocytic alterations and their contribution in the diagnosis of cases of thrombocytopenia.Materials and Methods: This was a cross-sectional study was conducted on all consecutive cases of bone marrow aspirates of thrombocytopenia over a duration of one year in BPKIHS. Megakaryocyte morphology was studied with a 100X objective. Data were entered into Microsoft excel 10 and analysed with SPSS version 11.5. Descriptive statistics charted and Chi-square tests were done for inferential statistics to find any association at 95% Confidence Interval.Results: Among the 38 subjects, megakaryocytic thrombocytopenia (44.7%) was the most common cause of thrombocytopenia.  Hypolobated megakaryocytes (63.2%), bare megakaryocytic nuclei (57.9%) were the common morphological changes in megakaryocytes. Odds of increased megakaryocyte count in megakaryocytic thrombocytopenia was found to be 12.5 times than for other causes of thrombocytopenia and the presence of bare megakaryocytic nuclei in MTP was statistically significant. (p –value<0.05)Conclusion: Many similarities were observed in megakaryocytic morphology among different hematological diseases. However, increased megakaryocyte count and presence of bare megakaryocytic nuclei, hypolobated forms were significant in megakaryocytic thrombocytopenia.

Observation of Gravitational Waves from a Binary Black Hole Merger

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

Prospects for Observing and Localizing Gravitational-Wave Transients with Advanced LIGO and Advanced Virgo

We present a possible observing scenario for the Advanced LIGO and Advanced Virgo gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We determine the expected sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron-star systems, which are considered the most promising for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5 deg2 to 20 deg2 will require at least three detectors of sensitivity within a factor of ∼ 2 of each other and with a broad frequency bandwidth. Should the third LIGO detector be relocated to India as expected, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

Cost-benefit analysis of avian influenza control in Nepal

Numerous outbreaks of highly pathogenic avian influenza A strain H5N1 have occurred in Nepal since 2009 despite implementation of a national programme to control the disease through surveillance and culling of infected poultry flocks. The objective of the study was to use cost-benefit analysis to compare the current control programme (CCP) with the possible alternatives of: i) no intervention (i.e., absence of control measures [ACM]) and ii) vaccinating 60% of the national poultry flock twice a year. In terms of the benefit-cost ratio, findings indicate a return of US $1.94 for every dollar spent in the CCP compared with ACM. The net present value of the CCP versus ACM, i.e., the amount of money saved by implementing the CCP rather than ACM, is US $861,507 (the benefits of CCP [prevented losses which would have occurred under ACM] minus the cost of CCP). The vaccination programme yields a return of US $2.32 for every dollar spent when compared with the CCR The net present value of vaccination versus the CCP is approximately US $12 million. Sensitivity analysis indicated thatthe findings were robust to different rates of discounting, whereas results were sensitive to the assumed market loss and the number of birds affected in the outbreaks under the ACM and vaccination options. Overall, the findings of the study indicate that the CCP is economically superior to ACM, but that vaccination could give greater economic returns and may be a better control strategy. Future research should be directed towards evaluating the financial feasibility and social acceptability of the CCP and of vaccination, with an emphasis on evaluating market reaction to the presence of H5N1 infection in the country.

Clinicoradiologic Evaluation of Eagle’s Syndrome and its Management

Background Eagle’s syndrome (Elongated styloid process) is often misdiagnosed due to its vague symptomatology. The diagnosis relies on detail history taking, palpation of styloid process in tonsillar fossa and imaging modalities.Objective To assess the length and medial angulation of elongated styloid process with the help of three dimensional computed tomography (3D CT) scan and to describe our clinical and surgical experience with patients suffering from Eagle’s syndrome.Method Prospective, analytical study conducted from August 2011 to August 2012 among 39 patients with Eagle’s syndrome. Detailed history taking, clinical examination and 3D CT scan was performed. Length and medial angulation was calculated. Patients with styloid process length longer than 2.50 cm underwent surgical excision via intraoral approach. Medial angulation of styloid process on both sides was correlated with each other using rank correlation coefficient. Wilcoxon Signed Rank test was applied to test significant difference between pre-operative and post-operative symptoms scores.Result Significant positive correlation was found between the medial angulation of styloid process on right side and left side (? =0.81, p<0.001). Significant difference was also observed between pre and post-operative symptoms scores (z=-5.16, p<0.001) .Conclusion Possibility of Eagle’s syndrome should always be considered while examining patients with vague neck pain. 3D CT reconstruction is a gold standard investigation which helps in studying the relation of styloid process with surrounding structures along with accurate measurement of its length and medial angulation.Kathmandu Univ Med J 2013; 11(4): 305-309

Errors : Detection and minimization in histopathology laboratories

The histopathological diagnosis plays a major role in the treatment of diseases. Errors in these reports affect patient care. Hence, it is of utmost importance for all practitioners of this specialty to be aware of possible errors in histopathology laboratories and the means to minimize them. As with other disciplines of laboratory medicine, errors can occur in the pre-analytical, analytical and post analytical phase. The concept of quality and its control should be applied to all phases to curb errors. Audit can be used as a tool to generate information about the background level of errors in pathology which in turn can be used to reduce and avoid errors in histopathology laboratory. Furthermore, accreditation is a means to ensure patient safety and best quality assurance.      

Primary intraosseous lymphoma at right femur

Lymphomas, the malignant neoplasms of the reticuloendothelial and lymphatic system, are classified based on characterisitic morphological pattern, immunophenotypic pattern and sometimes distinctive chromosomal aberrations. Most of the intraosseous lymphomas should be metastatic, and primary intraosseous lymphoma is a rare type of lymphoma, which accounts for only about 5% extranodal lymphoma. It accounts for approximately 3% of all primary bone malignancies.We report a case of 54 years lady presented with pain over  right thigh since 3 to 4 months which suddenly increased. The clinico-radiological differential diagnosis was fibrous dysplasia, plasmacytoma or metastasis.The histological findings and immunohistochemistry being positive for CD20 and BCL2 negative are those of Lymphoma- Diffuse large B cell type. Radiotherapy and/or chemotherapy is the preferred modality of management.

Changing perspective on tissue processing - comparison of microwave histoprocessing method with the conventional method

Background: Histopathological examination of tissues requires sliver of formalin fixed tissue that has been chemically processed and then stained with Haematoxylin and Eosin. The time honored conventional method of tissue processing, which requires 12 to 13 hours for completion, is employed at majority of laboratories but is now seeing the