bluuebunny/crossref_metadata_2025 huggingface dataset:
Diplomuddannelse i Erhvervspædagogik
Authors: Duch Henriette , Lang Nanna Ruengkratok , Nielsen Mette Thorsager
Published: September 2022

«Udvikling af praksis» er indskrevet som mål på Diplomuddannelsen i Erhvervspædagogik (DEP). Det er dog ikke konkretiseret, hvad udvikling af praksis vil sige. Denne artikel har til hensigt at synliggøre, hvad udvikling af praksis kunne være på DEP, samt hvad der ser ud til at være betydningsfuldt for arbejdet med udvikling af praksis. Baggrunden herfor er bekendtgørelsens formålskrav om udvikling af praksis samt erfaringer med, at en vag definition af udvikling af praksis kan være svær at arbejde med for både studerende og undervisere.
Artiklen tager udgangspunkt i problemstillingen: Hvordan kan udvikling af praksis tage sig ud på DEP? Denne problemstilling udforskes gennem forskningsspørgsmålet: Hvordan kan der arbejdes med udvikling af praksis som en del af afgangsprojektet på DEP, og hvilken betydning har kontekstuelle og individuelle faktorer for dette arbejde? Artiklen baserer sig på et kvalitativt studie, hvis formål er at bidrage til didaktisk udvikling, så de studerende kan understøttes i at udvikle praksis. Studiet er et forløbsstudie med en intervention på afgangsprojektet, hvori indgår et fokusgruppeinterview med de studerende.
Analysen er inspireret af Billetts og Erauts forskning, der begge er optaget af forholdet mellem uddannelse og arbejdsplads, samt Dalins beskrivelse af skoleudvikling. Analysen viser, at udvikling af praksis på DEP både kan tage sig ud som udvikling af undervisning og udvikling af organisationen. Resultaterne peger på, at det giver varierende forløb for de studerende, der også påvirkes af, hvordan relationer til kolleger, ledere og andre aktører indgår, og det kan være væsentligt at tænke ind i didaktikken med henblik på at understøtte de studerende i at udvikle praksis.
Comparison of Rate of Tooth Movement, Root Resorption and Pulp Vitality during En masse Anterior Retraction with Micro-osteoperforation and Low Level Laser Therapy: A Randomised Clinical Trial
Authors: Joseph Allen , Prashantha GS , Sabrish Sharanya , Sagarkar Roshan , Mathew Silju
Published: September 2022

Introduction: Micro-osteoperforation (MOP) and Low Level Laser Therapy (LLLT) are rapidly gaining popularity in clinical practice due their proven success in accelerating tooth movement and acceptable patient compliance. However, literature shows an inconsistent and variable evidence of their iatrogenic effects on the root and pulp due to biological variations of the samples chosen by the previously studies. Aim: To evaluate and compare the rate of tooth movement, changes in amount of external root resorption and pulp vitality in teeth during en masse anterior retraction associated with MOP and LLLT using split mouth technique. Materials and Methods: This was a double blinded, single center split mouth randomised clinical trial conducted at Faculty of Dental Sciences, MS Ramaiah University of Applied Sciences, Bangalore, Karnataka, India from March 2019 to October 2019. Total of 11 patients with bimaxillary dentoalveolar protrusion which required all four first premolar extractions were included in the study. Nickel Titanium (NiTi) closed coil springs were used for en masse retraction in upper and lower arches with force of 150g per side. Root resorption of all anterior teeth was evaluated using Cone Beam Computed Tomography systems (CBCT) and pulp vitality was checked using cold test after 4 months. The data was entered in Microsoft excel and the Statistical Package for Social Sciences software (SPSS) version 18.5 (SPSS Inc, Chicago) software was used for data entry and statistical analysis. A p-value of less than 0.05 was considered as statistically significant. Results: Total of 11 patients in which 9 were females and 2 males aged between 18-30 years with mean age 19±4.21 year, participated in this trial. LLLT (4 mm) and MOP (4.05 mm) showed similar performance in acceleration of tooth compared to each other. The overall root resorption was more in the experimental groups (LLLT- 2.60 mm, MOP- 2.84 mm) compared to the allotted controls. However, the canine showed less root resorption in both the experimental groups compared to the control. The overall root resorption was similar in both the experimental groups. The canine in LLLT group (0.30 mm) showed less root resorption compared to canine in MOP group (0.59 mm). There was no change in the pulp vitality status in both the experimental groups and the control groups. Conclusion: The overall root resorption in a given quadrant increases with increased rate of tooth movement. The tooth which was subjected to acceleratory orthodontic technique showed less root resorption compared to control. The tooth subjected to LLLT showed less root resorption as compared to the tooth subjected to MOP.
Oncological Outcomes of Primary Renal Malignancies other than Clear Cell Renal Carcinoma: A Retrospective Study from a Tertiary Centre in Southern India
Authors: Manikandan Ramanitharan , Mehra Ketan , Dorairajan Lalgudi Narayanan
Published: September 2022

Introduction: A lot of research is available about clear cell Renal Carcinomas (ccRCC). But there are lesser known facts about other subtypes of renal malignancies. With advances in immunohistochemical and cytogenetic techniques, new variants of renal tumours are being increasingly reported. The treatment and prognosis of such rare malignancies is still an enigma. Aim: To analyse the incidence, clinicopathological features, surgical treatment, and survival of non clear cell RCC at the tertiary care centre. Materials and Methods: The present study was a retrospective study in which histopathological reports of 77 nephrectomy specimens who underwent surgical treatment for suspected renal tumours from 2013-2018 were reviewed. Of which 19 (24%) patients had documented uncommon histologic variants of RCC. The clinical, demographic, and histologic characteristics of these patients were analysed, and survival was evaluated. The characteristic light microscopy and immunohistochemical features of these lesions were documented. Results: Mean age was 45 years (21-67 years). Out of 19 patients, 14 (73.6%) were males, and 5 (26.4%) were females. Mean tumour size was 8.8 cm (range 6-36) in the largest dimension. About 17 (22%) patients underwent radical nephrectomy, and 2 (2.5%) were treated with partial nephrectomy. Patients with collecting duct, synovial sarcoma, and primitive Neuroectodermal tumour (PNET) had associated inferior vena caval thrombus and underwent venous thrombectomy. Adjuvant treatment in the form of chemotherapy was instituted in collecting duct, adult Wilms and pure sarcomas. There was no mortality in the papillary carcinoma, and the worst prognosis was encountered in collecting duct carcinoma. Conclusion: Papillary variant had a good outcome as compared to other non clear cell carcinomas. RCC with sarcomatoid variant has a poor prognosis. Variants like renal sarcomas are rare but can be managed by nephron sparing surgeries with adjuvant therapies.
A Peculiar Three-way Connection: Colo-urachal-vesical Fistula with Cutaneous Extension
Authors: Vyas Ankit , Mulkalwar Alhad , Singh Kamlesh , Patil Bhushan
Published: September 2022

Urachal anomalies are quite a rare phenomenon in adults. This report is about a patient of a colo-urachal-vesical fistula with cutaneous extension. A 68-year-old diabetic male patient presented with purulent umbilical discharge since 15 days. Investigations revealed a colo-urachal-vesical fistula communicating with the umbilicus. He underwent a colo-urachal fistula excision with sigmoid-colectomy and bladder-cuff-excision. A thorough literature search revealed only nine reported cases thus-far. While the most common symptom was feculent umbilical discharge, this patient had a slightly varied-presentation of purulent-discharge. This is also the first study to conclusively demonstrate a vesical connection along with colo-urachal and cutaneous extensions.
Association between Preoperative RBC Parameters with Serum VEGF in Women Diagnosed with Breast Carcinoma: A Case-control Study
Authors: Gowda Apoorva P , Rekha TS , Subbarao MVSST , Bovilla Venugopal R
Published: September 2022

Introduction: The complete blood count is the first investigation to be done in every patient with breast carcinoma before surgery. Vascular Endothelial Growth Factor (VEGF) plays a major role in angiogenesis, metastasis and progression of tumours. Aim: To assess Red Blood Cell (RBC) parameters in breast carcinoma patients and controls, and to evaluate its relation with serum VEGF. Materials and Methods: Present study was a case-control study, conducted in Department of Pathology of JSS Medical College and Hospital, Mysuru, Karnataka, India from November 2019 to April 2021. Preoperative venous blood samples were collected and run in an automated analyser Mindray CAL6000 for all haematological parameters. Preoperative serum samples were collected and serum VEGF was estimated using the Enzyme Linked Immunosorbent Assay (ELISA) method. Statistical analysis was performed with Statistical Package for the Social Sciences (SPSS) version 22.0 to evaluate the association between RBC parameters and serum VEGF using Mann-Whitney U test. Results: A total of 80 samples were evaluated, which included 40 preoperatively diagnosed breast cancer cases and 40 age and sex matched controls. RBC parameters such as RBC, Haemoglobin (Hb), Haematocrit (Hct), red cell indices Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin (MCH), Mean Corpuscular Haemoglobin Concentration (MCHC), reticulocytes, Red cell Distribution Width (RDW) and nucleated RBCs (nRBCs) were measured. The nRBCs and serum VEGF of cases were significantly higher than controls. A statistically significant association between patients with low Hb and high serum VEGF was found. Conclusion: A higher percentage of breast carcinoma cases with anaemia in this study was significantly associated with high serum VEGF, reflecting anaemia induced hypoxia may trigger the tumour cells to secrete VEGF.
Indigenous People’s Engagement in Sand Mining and Its Impact on their Economy, Health and Environment: The Case of Batak in Palawan, Philippines
Authors: Tajolosa Teresita D. , Tajolosa Ric A.
Published: September 2022

Aims: To identify the impact of sand quarrying activities on the health, economy and environment of the Batak community whose people are dwindling in population. Further, the study aims to determine how the people demonstrate resilience in this face of economic adversity.

Study Design:  Using a qualitative research design and an interview as data collection              method.

Place and Duration of Study: Batak community in Sitio Mangapin in Barangay Langogan, Northern Puerto Princesa, January to June of 2019. 

Methodology: We invited 20 adult Batak who were engaged in small scale quarrying at the time of the study. The purpose of the study was explained to them and they were invited to participate in interviews. Only nine males and eight females signed the informed consent. Seventeen members of the community became the respondents in the study. The informants’ age ranges from 25 to 52 years old, all are married and have children and all were participants in small scale quarrying being done in the community. Casual interviews, focus group discussions and observations were used to collect data from the informants. Interviews were done individually and were recorded with permission of the informants.

Results: Data showed that families participated in the quarrying because of poverty but the engagement in hard labor impacts the health especially of the male workers in which 25 percent (of those interviewed) have acquired tuberculosis and persistent cough. About 50 percent of the women have acquired persistent back pain and loss weight. Observations yielded data on violations of the environment since the sand were taken not directly from the river but from the riverbank. Activities were found to be done on a large scale with trucks hauling from the river. While the Batak who were engaged in small scale mining, they were away the riverbanks in the process, creating large holes on the side which could potentially result in flash floods during rainy days.

Conclusion: the Batak are aware that the small economic benefits they acquire from participation in the quarrying do not outweigh the potential environment and health risks the community is exposed to in their engagement to this kind of work. Despite the awareness of the hazards posed by sand mining on their health and environment, the need to survive hunger and illness during the lean months and lack of government support had prompted the people to engage in small scale quarrying which could potentially worsen the damage being created by large scale sand mining already taking place in the river. Participation in small scale mining has become an adaptation strategy employed by the Batak workers to cope with economic difficulties.
Effect of Hours of Exposure to Cement Dust on Cancers Markers on Cement Workers in Port Harcourt
Authors: Nyebuchi Jonathan , Jumbo Mieiwari Ibifubara , Adjekuko Collins Ohwonigho , Okur Adams Matthew , Nwogu Arit Okechukwu
Published: September 2022

The study was aimed at evaluating the effect of cement dust exposure on cement loaders in Port Harcourt. The study was a cross sectional study which used convenient sampling size of 100 healthy male cement workers recruited in one cement depot and eight cement loading sites in Port Harcourt using simple random technique. Subjects were classified into three groups based on daily hour cement exposure; group 1 (1-5 hrs), group 2 (6-10 hrs) and group 3 (>10 hrs). Group 1 had 27 subjects, group 2 had 62 subjects and group 3 had 11 subjects. 4 ml of the venous blood was drawn into plain vacutainer bottles for the evaluation of Neuron specific Enolase, Vascular Endothelial Growth Factor A, and Total Antioxidant Status. ELISA method was used for the laboratory determination of VEGF-A and NSE while a colorimetric method was used for TAS estimation. Results showed TAS level among the classes was not significantly different (p=0.3304) and has the mean value of 2.02±0.40; 2.16±0.41 and 2.1 ±0.41 in groups 1, 2 and 3 respectively. VEGF-A level among the classes was not significantly different (p=0.7123) with mean value of 406.00 ±234.80; 439.60 ±369.40 and 361.00 ±171.00 in groups 1, 2 and 3 respectively. The mean value for NSE level among the groups (1, 2, and 3) were 3.78±1.49; 4.17±2.91 and 3.42±0.98 but there was no significantly difference (p=0.5551). This has shown that hourly exposure to cement dust among healthy cement workers does not have significant impact on cancer markers (VEGF-A, NSE and TAS). A higher timeframe assessment may provide a better picture of the effect of cement dust exposure since many diseases associated with cement dust exposure are chronic.
Comparative Analysis of Heavy Metals Concentration in Soil and Vegetable (Capsicum annum) Collected from Two Sampling Sites (Farmland and Dumpsite) and the Effect on Plant DNA
Authors: Adu A. A. , Aderinola O. J. , Ogbe A. A. , Giwa T. F. , Salaam I. O.
Published: September 2022

The levels of heavy metals and their effect on the DNA of Capsicum annuum collected from dumpsite (in Ojota) and farmland (in Badagry) in Lagos, Nigeria, were examined using standard procedures.

The results of concentration of heavy metals in the soil for the farmland and dumpsite respectively are: Zn (882.0 ±0.006mg/kg, 14316.8±1.009mg/kg), Cr (2.006 ±0.002mg/kg,3.888± 0.002mg/kg), Cd (0.098 ± 0.001mg/kg, 0.644 ± 0.002mg/kg), Cu (0.206± 0.001mg/kg, 0.997 ± 0.001mg/kg) and Pb (0.005 ± 0.003mg/kg, 0.843± 0.002mg/kg) respectively. The values of N (3153.6± 0.008mg/kg, 4191.2± 0.006mg/kg), P (7598.3 ± 0.009mg/kg, 8794.5 ± 0.003mg/kg) and K (113.56 ± 0.004mg/kg, 532.12 ± 0.004mg/kg) were recorded in the soil from farmland and dumpsite respectively. While the values of N, P, and K in soil from dumpsite were higher (p<0.05) than that from farmland, the only value of Zn in the soil of dumpsite was significantly higher than in soil from farmland. Similarly, the values of all metals except Zn recorded in the leaf, stem, and root of C. annuum showed no significant difference between the sample collected from dumpsites and farmland. The values of Zn in leaf, stem, and root of C. annuum from farmland were significantly higher (p<0.05) than that of the dumpsite.  The DNA bands of the Capsicum annuum from the control site have a clearer band spectrum than that from the dumpsite site, however, there was no DNA mutation. In conclusion, C. annuum collected from both farmland (in Badagry) and dumpsite (in Ojota) contained minerals and heavy metals whose concentrations were still within standard permissible limits. Thus, C. annuum from both sites is safe for human consumption.
Applications in Some Area-Biased Distribution
Authors: Celik Nuri
Published: September 2022

The preference of the proper distribution for modelling data is often a substantial concern to researchers and practitioners. For this reason, new statistical distributions or the generalizations of well-known distributions have been proposed for exible modeling. Weighted distributions are one of the generalization methods for these distributions. In this article, area biased beta, Rayleigh and log-normal distributions are introduced. Some main statistical properties, like probability density functions, cumulative distribution functions, moments and the estimation of the parameters of these distributions are obtained. Real data examples are used for illustration of these distributions.
Effects of Drug Addiction on Young Generation: A Sociological Investigation in Dinajpur District, Bangladesh
Authors: Durud Mohammad Saifuddin , Bhattacharya Rahul
Published: September 2022

In Bangladesh, recently drug addiction is considered as a major problem, because our young generation is highly involved with the issue. Drug is now the curse of a society. This curse has polluted our society to its core. 200 million people around the world are into drug abuse most of who are teenagers. Bangladesh does not produce drugs, but the global environment has made it a dangerous place for drug abuse. Besides, urbanization, population growth, widespread use of the internet and lack of awareness has made drug abuse an epidemic. The drug scenario in Bangladesh has changed with time. Drug addiction is turning to the national problem from social problem. It creates many other problems. This study conducted to identify the core cause of drug addiction of young generation. To conduct this research, questionnaire survey and case study have conducted. Case study tried to bring out the core factor responsible for the drug addiction of young generation and questionnaire survey expressed the people’s perception toward drug addiction. These research findings suggest that influence of peer group; weak family bonding, affluence and shortage of money are the key responsible factor for the drug addiction of young generation in Bangladesh.
Impact of Certain Fungicides and Calcium Nitrate on Quality and Shelf Life of Kinnow Mandarin
Authors: Sukrampal . , Rana G. S. , Vikalp . , Mor Rajesh , Jat M. L. , Bishnoi Mukesh
Published: September 2022

An experiment was carried out at Chaudhary Charan Singh Haryana Agricultural University, Hisar during the year 2019-20 to study the effect of different fungicides and calcium nitrate on the quality and shelf life of Kinnow mandarin”. A spray of carbendazim, copper oxychloride, mancozeb, propiconazole, nimbecidine, calcium nitrate, and their combinations were done ten days prior to harvesting on ten years old Kinnow plants. When compared to fruits from untreated plants, the fruits from plants treated with fungicides, nimbecidine, calcium nitrate, and their mixtures showed much less rotting. The most successful treatment for preventing fruit rot after harvest was carbendazim 0.05% + calcium nitrate 1%, followed by propiconazole 0.05% + calcium nitrate 1%. with various pre-harvest treatments, it was discovered that the Total dissolved solids (TSS), acidity, TSS/acid ratio, reducing sugar, non-reducing sugar, and total sugar of Kinnow fruits were not significantly affected. Among all the treatments, the maximum ascorbic acid content (24.10 mg/100 ml of juice) was reported in mancozeb 0.2% + calcium nitrate 1% and propiconazole 0.05% + calcium nitrate 1% during storage in Kinnow fruits. The most prominent pathogens associated with decay loss were identified as Colletotrichum gloeosporioides, Diplodia natalensis and Penicillium sp. during the storage period.
Effect of Seaweed Extracts on Growth, Yield, and Quality of Fruit Crops: A Review
Authors: Patel J. J. , Mangroliya R. M. , Patel N. A.
Published: September 2022

Seaweed or Marine macro-algae are often regarded as an underutilized bioresource, many have been used as a source of food, raw materials for industry, and therapeutic and botanical purposes for decades. Moreover, several plant growth-stimulating compounds found in seaweed and products derived from seaweed have made them popular supplements to crop production systems. This article provides an in-depth analysis of how different seaweed species and seaweed products affect the plant growth and development of fruit crops. They also increase plants' biochemical components and can alleviate abiotic stress.
Synthesis and Characterization of Bioactive Schiff Base Ligand Derived from 2-hydroxy-1-napthaldehyde and 4-aminobenzonitrile and its Co(II), Ni(II) and Cu(II) Complexes
Authors: Ado Ibrahim , Na’aliya Junaidu , Haleelu Mustapha M. , Sani Salihu , Zayyan Rabi S.
Published: September 2022

The Schiff base derived from 2-hydroxy-1-napthaldehyde and 4-aminobenzonitrile and its corresponding Co(II), Ni(II) and Cu(II) complexes were synthesized and characterized by means of FT-IR spectroscopy, thermal analysis, powder x-ray analysis (PXRD), conductivity measurement, magnetic susceptibility  and elemental analysis. The mononuclear complexes have been obtained by liquid-assisted mechanochemical method. The Schiff base was synthesized in high yield > 90% with negligible waste. FT-IR study indicates a strong band in the spectra of the Schiff base at 1577 cm-1 assigned to azomethine v(C=N) stretching vibration which shifted to new frequency regions in the spectra of complexes indicating the formation of the anticipated complexes. The Schiff base melted at 197oC while decomposition temperatures of the complexes were in the range of 265 - 300oC, signifying good thermal stability. Molar conductance values were in the range of 4.39 - 1349 Ω-1cm2mol-1, indicating non electrolytic nature of the synthesized complexes. Magnetic susceptibility measurement showed that Co(II), Ni(II)  and Cu(II) complexes are  paramagnetic and exhibit magnetic moment in the range of 1.50 - 3.19 BM, the values correspond to the tetrahedral geometry. The relative percentage of the constituent elements (C, H, N) obtained from CHN analysis and calculated values using the proposed structures are similar and are in good agreement. The Schiff base and metal complexes were evaluated as agent for inhibiting growth of pathogenic bacteria using disc diffusion method. The results indicated that metal complexes are more active compared to Schiff base ligand against the test organisms.
HBV Genetic Diversity and Transfusion Safety: A Conceptual Analysis and Integrative Model
Authors: Maulot-Bangola Denis , Fokam Joseph , Mangala Christian , Nkoa Thérèse
Published: September 2022

Background: Blood transfusion carry the risk of transmitting blood-borne infections. HBV genetic diversity and transfusion safety are concepts that are increasingly used in public discourse. However, how the concepts are used and how they are defined remains unclear. The objective of this study is to clarify the concepts emanating from the research project titled «Genetic diversity of HBV and its effect on the transmission risks in blood transfusion in Gabon» and to propose an integrative model of HBV genetic diversity-Transmission risks based on these results.

Methods: Three databases were used in the Quantitative analysis: Pubmed, Medline and Google Scholar. The researchers delimited the search to full articles in the databases. The eligibility criteria were based on published studies in English between January 2012 and December 2020, looking at the HBV genetic diversity and the transfusion safety. The Cochrane tool was used to assess the risk of bias. A systematic review was performed on concepts and definitions. Eligible publications were reviewed using concept analysis that led to the extraction of text data for the themes “definition”, “attributes”, “antecedents”, “consequences”, and “related concepts”. The quantitative methods was used to quantify the associations between HBV Genetic diversity and transmission risk examined in the literature.

Results: A total of 2685 records were identified by primary and secondary search, of which 802 were retained after examination of titles and abstracts. A total of 144 (18%) publications were included in the review, 123 dealing with Hepatitis B Virus, 38 with Genetic diversity, 94 with Transfusion safety and 94 with Transmission risks were all coded. The final concept coding scheme contained 14 items, each with a satisfactory inter-author reliability score (r) (r ranging from 0.6 and 1), coding Hepatitis B Virus, Genetic diversity, Transfusion safety, Transmission risks, Blood donation-transmission risks, Demographic factors-transmission risks, HBsAg- transmission risks, Anti-HBc-transmission risks, Viral load-transmission risks, measurement errors- transmission risks, viral load-HBsAg, viral load-Anti-HBc, Sequencing-viral load, Genotype- transmission risks. In the resulting integrative model, the elements were mapped to different levels of care.

Conclusion: This integrated theory suggests a number of directions to improve the understanding of transfusion safety in the context of HBV genetic diversity, to speak the same language. It provides a basis for creating better measures and interventions in transfusion medicine.
New Equations for Energy Dissipation down a Stepped Spillway
Authors: Ozueigbo Okechukwu , Agunwamba J. C.
Published: September 2022

Stepped spillways use their stepping nature to substantially dissipate energy in floodwater. Many researchers investigated the hydraulic and geometric relationships of the stepped spillway with a dam slope above 26.6o degrees that resulted in energy dissipation. But few studied stepped spillways with a dam slope below 26.6o degrees that also resulted in energy dissipation with even fewer proposing models that estimated its energy losses. This resulted in limited information and guidelines for designers of stepped spillways involved with slopes below 26.6o degrees. The authors reviewed researchers' publications on horizontal stepped spillways with dam slopes between 3.4o ≤ θ ≤ 26.6o conducted in transition and skimming flows in large-size facilities with phase-detection intrusive probes. They obtained data sets from them, which they reanalyzed to develop 2 new energy dissipation models that govern skimming flows over a wide range of operating conditions. The data from the new models compared well with the measured data in terms of energy dissipation with high coefficients of correlation between 0.95 and 0.99. All data were in good agreement independent of channel slopes, stepped configuration, and sensor size. The models are simple, easy to use, and render more accurate results than the existing model.
In vitro potency and stability of fortified ophthalmic antibiotics
Authors: Md Mustafa Kemal Arıcı , Md Zeynep Sümer , Md Cenap Güler , Md Orhan Elibol , PhD Gülendame Saygı , PhD Salih Çetinkaya
Published: July 2002

Purpose: This study evaluates the in vitro potency, stability and contamination of the fortified ophthalmic antibiotic preparations of cefazolin, vancomycin, gentamicin and tobramycin stored for 4 weeks. The effects of the different solvents and storage temperatures on the antimicrobial potency and stability were also examined.

Methods: The fortified stock solution of cefazolin and vancomycin were prepared by reconstituting with 0.9% sodium chloride and with artificial tears. Gentamicin and tobramycin were prepared by adding parenteral forms into their commercial ophthalmic solutions. The antimicrobial potency was measured by the minimum bactericidal concentration for cefazolin (33.3 mg/mL) and vancomycin (31 mg/mL) against Staphylococcus aureus, and for tobramycin (13.5 mg/mL) and gentamicin (13.5 mg/mL) against Pseudomonas aeruginosa. The stability of solution was evaluated by measuring absorbance spectra and pH. During the study period the levels of contamination of the stock solutions were examined by culturing on blood and on Sabouraud‐dextrose media.

Results: There were no differences in the antimicrobial potency of the cefazolin, vancomycin and tobramycin within the 4‐week period; however, the potency of gentamicin was decreased at both temperatures after 21 days. It was found that different solvents or storage temperatures had no effect on the potency. Throughout the 4‐week period, no change was found in the absorbance spectra of gentamicin and tobramycin, whereas the absorbance spectra of cefazolin and vancomycin stored at 24°C increased in both of the solvents used (P < 0.05). In all of the antibiotics, pH changed at 24°C after 7–10 days; however, at 4°C, only the pH of tobramycin exhibited changes after 14 days (P < 0.05). No contamination was detected in the stock solutions during the study period.

Conclusion: Topical fortified antibiotic solutions used for longer than 7 days should be stored at ≤ 4°C, those stored at 24°C should be discarded after 7 days.
Treatment of Migraine With Rizatriptan: When to Take the Medication
Authors: Hu X. Henry , Raskin Neil H. , Cowan Robert , Markson Leona E. , Berger Marc L. , On Behalf Of The United States Migraine Study Protocol (USMA
Published: July 2002

Objective.—To assess, in the setting of routine clinical practice, rizatriptan's effectiveness in treating acute migraine at its onset versus in a later phase of the attack.

Background.—Although the efficacy and tolerability of rizatriptan have been well documented in clinical trials, no information is available about the impact of the timing of medication use on clinical outcome.

Methods.—Migraineurs were enrolled in a prospective study and treated with rizatriptan 10 mg for two migraine attacks. Patients reported how they used the medication and treatment outcomes via an interactive voice response system. Outcome variables assessed included: time to onset of headache relief, headache severity 2 hours postdose and whether or not patients became largely symptoms‐free (including associated symptoms), and when they were able to resume normal activities. Episodes in which patients took rizatriptan immediately after experiencing headache were designated “early use” and those in which patients delayed treatment until their headaches evolved to become moderate or severe were designated as “delayed use.” Generalized estimating equations were used to assess the impact of early drug use and to control for age, gender, drug formulation, use of other migraine prescription medications before taking rizatriptan, attack sequence, migraine attack frequency, and recent migraine severity.

Results.—A total of 1919 migraineurs with 3450 migraine attack episodes were evaluated, of which 1369 episodes were early use and 2081 delayed use. Compared to delayed‐use episodes, episodes wherein patients took rizatriptan early were 1.33 times more likely to be characterized by onset of headache relief within 30 minutes posttreatment (95% confidence interval [CI], 1.11 to 1.60), 1.32 times more likely to result in a largely symptom‐free state (95% CI, 1.12 to 1.57), and 1.34 times more likely to be associated with a return to normal activities (95% CI, 1.13 to 1.58) within 1 hour posttreatment. No significant difference between early‐use and delayed‐use episodes was observed with respect to the likelihood of there being no or mild headache 2 hours posttreatment (odds ratio, 1.05; 95% CI, 0.90 to 1.24).

Conclusions.—Whether taken at headache onset or later in the attack, rizatriptan was equally effective in relieving acute migraine headache by 2 hours postdose. Taking rizatriptan at the onset of headache was associated with more rapid relief of headache and reversal of functional disability.
The Difference in Perceptions of Educational Need Between Epilepsy Patients and Medical Personnel
Authors: Choi‐Kwon Smi , Yoon Sun Moo , Choi Mi Ri , Kang Dong‐Wha , Lee Sang Kun
Published: July 2002

Summary:  Purpose: This study was undertaken to determine what patients with epilepsy need to know about their condition, and to discern what differences exist between patients' perceptions of this need and the medical profession's perception of what patients should know.

Methods: Seventy‐five consecutive patients with epilepsy and 56 medical personnel (residents and nurses) who were working in either Neurology or Neurosurgery Units were studied using a structured questionnaire consisting of 3 subsets with a total of 27 questions.

Results: Using a Likert scale, epilepsy patients gave high priority to their need for more information about “how epilepsy is diagnosed,”“the structure of the brain” (p < 0.05, p < 0.01, respectively), and “the diet that might prevent the attack” (p < 0.05) than did medical personnel. Our study also revealed that men were more concerned with questions regarding smoking and drinking than were women (p < 0.05, respectively), whereas married patients gave higher scores in the category of employment (p < 0.01) and contraception/pregnancy (p < 0.05) than did unmarried patients. The patients with one or more seizures per month rated higher scores on questions concerning the first aid at the time of attack and dosage of antiepileptic drugs (AEDs; p < 0.05, respectively) than did the patients with fewer than one seizure per month. The patients taking poly‐AED treatment gave higher scores on six items related to AED therapy than did those receiving monotherapy. No significant differences were found with regard to the length of time patients had the condition, nor to educational level or current employment status.

Conclusions: An educational program for epilepsy patients should be developed on the basis of understanding that there are differences in perspectives among patients with different sociocultural contexts as well as between patients and medical personnel.
Interaction of Rayleigh–Taylor mode with shear-flow and vortex-flow in magnetized plasmas
Authors: Chakrabarti Nikhil
Published: July 2002

A two-dimensional vortex subjected to shear flow is considered in Rayleigh–Taylor mode of magnetized plasmas. It is shown that, when vortex-flow is almost absent, linear instability is suppressed due to shear-flow. In the presence of a vortex, however, there is a possibility of secondary instability excitation. It is demonstrated that the efficiency of this secondary instability depends on the sense of rotation and strength of vortex-flow and shear-flow.
Magnetohydrodynamic waves in a homogeneous plasma convected uniformly at relativistic speed
Authors: Kalra G. L. , Gebretsadkan W. B.
Published: July 2002

The plasma in several physical situations such as movement of electrons along the geomagnetic field lines in the magnetosphere, the movement of the ionosphere, propagation of cosmic rays, etc., can be appropriately simulated by a drifting relativistic model. Keeping this in view, a general dispersion relation for magnetohydrodynamic (MHD) waves has been derived in a laboratory stationary coordinate system with respect to which plasma is drifting with a velocity which need not be small compared with the speed of light. This dispersion relation gives several earlier well-known results for MHD waves supported by an ideal relativistic plasma. The characteristic equation for arbitrary direction of propagation with reference to the ambient magnetic field is quite unwieldy. So, the detailed discussion is confined to the special cases when the propagation vector is along or across the magnetic field. However, wherever feasible, approximate solutions for arbitrary direction of propagation have also been discussed.
Cyclotron resonance in organic metals
Authors: Peschansky V. G. , Medina Pantoja J. C.
Published: July 2002

The velocity distribution of the charge carriers at the Fermi surface in layered organic conductors can be found from an experimental investigation of the cyclotron resonance in a magnetic field parallel to the layers.
The quantum conductance of ballistic microconstrictions in metals with an open Fermi surface
Authors: Namiranian A. , Kolesnichenko Yu. A. , Kolesnichenko Yu. A.
Published: July 2002

It is shown that the conductance G of a quantum microconstriction in a metal with an open Fermi surface undergoes jumps e2/h of the opposite sign as a function of the contact diameter. The negative jumps are a result of the limitation of the energy of the electron motion along the direction in which the Fermi surface is open. The point contact spectrum dG/dV of such a constriction has additional peaks at the bias eV where the maximum energy εmax of the quantum subband is equal to the energies εF±eV/2 (εF is the Fermi energy).
Features of the microstructure and low-temperature yield stress of quenched Al–Li alloys
Authors: Braude I. S. , Grigorova T. V. , Isaev N. V. , Pustovalov V. V. , Fomenko V. S.
Published: July 2002

The features of the microstructure of quenched Al–Li alloys with lithium concentration below the solubility limit (3.8 at. %) and above the solubility limit (7.0 and 10.4 at. %) are studied by the x-ray diffractometry. In addition to the standard structural reflections, the diffraction patterns of all the alloys show diffuse halos that fall off in intensity as the lithium concentration is increased. As a result of an analysis of the intensity of the diffuse scattering of x rays it is established that the observed halos are due to short-range order of the layered type in regions with a characteristic radius of 1.5 nm. The decrease in the intensity of the diffuse halo on the diffraction pattern of the alloy Al–10.4 at. %Li and the appearance of new structural reflections are explained by the precipitation of disperse particles of the δ′ phase. It is shown that these particles have a substantial influence on the mechanism of plastic deformation in these alloys in the temperature region 40–170 K.
Properties of solid He3 inclusions embedded in a crystalline He4 matrix at ultralow temperatures
Authors: Ganshin A. , Grigor’ev V. , Maidanov V. , Mikhin N. , Penzev A. , Polev A. , Rudavskii E. , Rybalko A.
Published: July 2002

A study is made of the kinetic properties of the quantum systems formed in dilute solid mixtures of He3 in He4 at ultralow temperatures as a result of the first-order phase transition known as phase separation. The system is a crystalline matrix of almost pure He4 in which small solid inclusions of almost pure He3 are embedded. Data on the inclusion growth kinetics, which is governed by diffusion processes in the matrix, are obtained using precise pressure measurements at constant volume. It is shown that impuriton quantum diffusion is the main process causing the inclusion growth at T>100 mK. At lower temperatures a strong suppression of quantum diffusion is discovered. This suppression can be associated with the elastic strains induced by the large difference in molar volume between the matrix and inclusions. The magnetic relaxation processes in such two-phase crystals are also investigated using a pulsed NMR technique. The spin–lattice and spin–spin relaxation in the inclusions are found to be practically independent of temperature. This can be described by exchange processes associated with the He3 tunneling motion. The values of the relaxation times are in good agreement with the corresponding times for pure bulk He3. In contrast with the case of pure solid He3, the exchange plateau region extends down to lower temperatures. The nuclear magnetic relaxation in the matrix can be described by the Torrey model, which is based on He3–4He tunneling exchange. The concentration dependence of the relaxation times coincides with that observed for homogeneous dilute mixtures of He3 in He4.
EXAFS studies of the trapping site structure for molecules isolated in cryogenic matrices
Authors: Roubin P. , Varin S. , Crépin C. , Gauthier-Roy B. , Flank A.-M. , Lagarde P. , Ténégal F.
Published: July 2002

We present here results concerning the first attempt of determining the trapping site structure of molecules isolated in inert matrices at low temperature by the EXAFS (Extended X-ray Absorption Fine Structure) method. The experiments have been performed at the K edge of argon, silicon, sulfur, and chlorine for pure solid argon, and for SiH4, OCS, and HCl isolated in different cryogenic matrices. The EXAFS technique is sensitive to the local environment around the absorbing atom, and the spectral features induced by the matrix material (Ar, Xe, N2, and CH4) are clearly evidenced here. The data allow a characterization of the double substitutional site for OCS in argon and xenon, while no structure can be determined for the accommodation of SiH4 in argon. A discussion of the best choice for the guest/host system to obtain a good EXAFS signal is included.
Electron transfer and vibrational modes in a finite molecular chain
Authors: Glushko E. Ya.
Published: July 2002

A statistical quantum discrete model for a molecular bridge between metallic electrodes is proposed. A theory of conduction is developed on the assumption that the main contribution to the electron transfer is due to nonequilibrium-populated electron-affinity states of the molecule. It is shown that the field-induced modification of the states of the bridge molecule, together with the Coulomb blockade effect, leads to suppression of the electron transfer. Relations are obtained for the electron–vibron interaction, and the contribution of atomic vibrations to the conductance of the chain is discussed. The current–voltage characteristics of molecular bridges are calculated for different positions of the spectrum of the molecule with respect to the levels of the chemical potentials of the electrodes. Explanations are given for the stepped and asymmetric character of the current–voltage characteristic observed experimentally and for the fractional charging of the bridge molecule.
Features of the temperature dependence of trapped magnetic flux in yttrium high-Tc superconducting ceramics
Authors: Sukhanov A. A. , Omel’chenko V. I.
Published: July 2002

The temperature dependence of the trapped magnetic field (TMF) Ht(T) in yttrium high-Tc superconducting (Y–HTSC) ceramic systems is investigated. For field-cooled trapping the Ht(T) curves are the same as Ht(Tt) (Tt is the trapping temperature): Ht decreases monotonically with increasing temperature, and in weak fields it goes rapidly to saturation as Tt is lowered. In the case of trapping with a magnetic field pulse after zero-field cooling the Ht(Tt) curves have a maximum, and Ht decreases monotonically with increasing T, the rate of this process being faster as the initiating field H is decreased, and the temperature at which the TMF vanishes decreases with decreasing Tt and H. A discussion of the results is presented, and it is shown that the observed features of the temperature dependence of the trapped magnetic flux in Y–HTSCs are not explained in terms of the Bean model but are satisfactorily described by a model in which the magnetic flux is trapped in superconducting loops.
Interaction energies of van der Waals and hydrogen bonded systems calculated using density functional theory: Assessing the PW91 model
Authors: Tsuzuki Seiji , Lüthi Hans P.
Published: July 2002

The performance of density functional theory using the Perdew and Wang’s exchange and correlation functionals (PW91) functional for the prediction of intermolecular interaction energies is evaluated based on calculations on the neon, argon, methane, ethylene, and benzene dimers, as well as on 12 hydrogen bonded complexes (water, methanol, formic acid, hydrogen fluoride, ammonia, formamide dimers and water–methanol, water–dimethyl ether, water–formaldehyde, hydrogen cyanide–hydrogen fluoride, water–ammonia, water–formamide complexes). The results were compared with those obtained from Becke’s exchange and Lee, Yang, and Parr’s correlation functionals (BLYP), Becke’s 3 parameter functional combined with Lee, Yang, and Parr’s correlation functional (B3LYP), second order Mo/ller–Plesset perturbation (MP2), and coupled cluster calculations with single and double substitutions and with non-iterative triple corrections [CCSD(T)] calculations. The calculated interaction energies show that the PW91 functional performs much better than the BLYP or B3LYP functionals. The error in the computed binding energies of the hydrogen bonded complexes is 20% in the worst case. The most demanding cases are the systems with large dispersion contributions to the binding energy, such as the benzene dimer. In contrast to the BLYP and B3LYP functionals which fail to account for dispersion, the PW91 functional at least partly recovers the attraction. The basis set dependence of the PW91 functionals is relatively small in contrast to the MP2 and CCSD(T) methods. Despite its occasional difficulties with dispersion interaction, the PW91 functional may be a viable alternative to the ab initio methods, certainly in situations where large complexes are being studied.
Nonlinear phenomena in phonon–ripplon oscillations in a two-dimensional electron crystal over liquid helium
Authors: Sivokon’ V. E. , Dotsenko V. V. , Kovdrya Yu. Z.
Published: July 2002

The characteristics of the spectra of phonon–ripplon oscillations of a two-dimensional electron crystal over liquid helium are investigated at temperatures of 70–500 mK, electron surface densities of (3–12)×108 cm−2, and clamping electric fields of 500–2300 V/cm. Experiments are done in a frequency range of 1–20 MHz. It is shown that at a low level of the exciting signal the characteristics of the spectra are well described by the self-consistent theory of phonon–ripplon oscillations in a crystal. As the exciting signal is increased there is a decrease in the frequencies of the fundamental harmonics of the oscillations, apparently because of a nonlinearity in the electron displacements in the depressions on the liquid helium surface. As the level of the exciting signal is increased further, new modes of phonon–ripplon oscillations begin to be excited in the crystal. These modes are either the theoretically predicted division resonances arising at large electron displacements or the asymmetric modes caused by the coupling of the oscillations of different modes owing to nonlinear effects and by plastic deformation processes.
Equilibrium magnetic characteristics of high-Tc superconductors with allowance for the spatial distribution of the order parameter in the vortex cores. I. Equilibrium magnetization
Authors: Mamsurova L. G. , Pigalskiy K. S. , Trusevich N. G. , Pogosov W. V.
Published: July 2002

An investigation is made into the accuracy of the theoretical description of the field dependence of the equilibrium magnetization M(H) of type-II superconductors with Ginzburg–Landau parameters κ≫1 in various approximations for magnetic fields H much less than the upper critical field Hc2. It is found that taking the spatial distribution of the order parameter into account has a substantial effect on the behavior of the magnetization M(H) even at the very lowest fields in the close vicinity of the lower critical field Hc1. The mechanisms through which and the degree to which the field dependence M(H) is influenced by such factors as the self-energy of the vortex, the accuracy of description of the spatial distribution of the vortex field, the suppression of the order parameter due to the overlapping of the vortices, and the use of the principle of superposition of fields are investigated for fields in the interval Hc1⩽H≪Hc2. In this field interval an analytical expression for M(H) is obtained by direct evaluation of the lattice sums with allowance for the influence of the structure of the vortex cores.