Effects of spin-orbit coupling on transmission and absorption of electromagnetic waves in strained armchair phosphorene nanoribbons

We compute the optical conductivity, both the imaginary and real parts of the dielectric constant, and the optical coefficients of armchair phosphorene nanoribbons under application of biaxial and uniaxial strains. The Kane-Mele model Hamiltonian has been applied to obtain the electronic band structure of phosphorene nanoribbons in the presence of a magnetic field. The effects of uniaxial and biaxial in-plane strain on the frequency behavior of the optical dielectric constant, and the frequency behavior of the optical absorption and refractive index of phosphorene nanoribbons have been studied, in terms of magnetic field, spin-orbit coupling and strain effects. Linear response theory and the Green's function approach have been exploited to obtain the frequency behavior of the optical properties of the structure. Moreover, the transmissivity and reflectivity of electromagnetic waves between two media separated by a phosphorene-nanoribbon layer are determined. Our numerical results indicate that the frequency dependence of the optical absorption includes a peak due to applying a magnetic field. Moreover, the effects of both in-plane uniaxial and biaxial strains on the refractive index of single-layer phosphorene have been addressed. Also, the frequency dependence of the transmissivity and reflectivity of electromagnetic waves between two media separated by armchair phosphorene nanoribbons for normal incidence has been investigated in terms of the effects of magnetic field and strain parameters. Both compressive and tensile strain have been considered for the armchair phosphorene nanoribbons in order to study the optical properties of the structure. In particular, the control of the optical properties of phosphorene nanoribbons could lead to extensive applications of phosphorene in the optoelectronics industry. Also, such a study of the optical properties of phosphorene nanoribbons has further applications in light sensors. Meanwhile, the effects of spin-orbit coupling on the optical absorption and transmissivity of electromagnetic waves in phosphorene nanoribbons could be a novel topic in condensed-matter physics.

Strain and magnetic field effects on the electronic and transport properties of γ-graphyne

In this paper, we apply a tightly binding Hamiltonian model in the presence of a magnetic field for investigating the electronic and transport properties of γ-graphyne layers. We also consider the effects of in-plane biaxial strain on the electronic behavior of γ-graphyne layers. Moreover the impact of strain on magnetic susceptibility and specific heat of the structure is also studied. In particular, the temperature dependence of static thermal conductivity of γ-graphyne layers due to magnetic field and strain effects is studied. We exploit the linear response theory and Green's function approach to obtain the temperature behavior of thermal conductivity, electrical conductivity and the Seebeck coefficient. Our numerical results indicate that thermal conductivity increases upon increasing temperature temperatures. This effect comes from the increasing thermal energy of charge carriers and their excitation to the conduction bands. The temperature dependence of Seebeck coefficient shows that the thermopower of an undoped γ-graphyne layer is positive on the whole range of temperatures in the absence of strain effects. The effects of both electron doping and magnetic field factors on temperature behavior of the electrical conductivity of γ-graphyne are investigated in detail. Moreover the effects of biaxial strain on thermal conductivity of single layer γ-graphyne have been addressed.

The effects of spin-orbit coupling on optical properties of monolayer [Formula: see text] due to mechanical strains

We have studied the optical conductivity of a quasi two-dimensional [Formula: see text] in the presence of external magnetic field and spin-orbit coupling. Specially, we address the frequency dependence of optical conductivity due to spin-orbit interaction. Using linear response theory the behavior of optical conductivity has been obtained within Green's function method. We have also considered the effects of uniaxial and biaxial in-plane strain on the optical absorption of [Formula: see text] layer. In the absence of external magnetic field with negative uniaxial strain parameter, optical conductivity includes Drude weight at zero frequency limit while Drude weight vanishes for [Formula: see text] layer under positive uniaxial strain. Our results show that the increase of uniaxial positive strain parameter causes to move the position peak to the higher frequencies. In contrast to uniaxial strain case, the Drude weight in optical conductivity appears at positive biaxial strain value 0.15. Also we have studied the effects of magnetic field, electron doping, hole doping in the presence of spin-orbit coupling on frequency dependence of optical conductivity of [Formula: see text] in details. The magnetic field dependence of optical absorption shows a monotonic decreasing behavior for each value of temperature in the absence of strain parameter.

Baclofen as a therapeutic option for gastroesophageal reflux disease: A systematic review of clinical trials

Background

The main components of gastroesophageal reflux disease (GERD) management include a combination of medications and lifestyle modifications; Nevertheless, based on the severity of symptoms and their response to medications, other treatments could be considered. Baclofen has been demonstrated in studies to relieve GERD symptoms. The current study aimed to precisely address the effects of baclofen on the treatment of GERD and its characteristics.

Methods

A systematic search was carried out in Pubmed/Medline, Cochrane CENTRAL, Scopus, Google Scholar, Web of Science, and clinicaltrials.gov up to December 10, 2021. The search terms included baclofen, GABA agonists, GERD, and reflux.

Results

We selected 26 papers that matched the inclusion criteria after examining 727 records. Studies were classified into four categories based on the study population and reported outcomes: (1) adults, (2) children, (3) patients with gastroesophageal reflux-induced chronic cough, (4) hiatal hernia patients. The results revealed that baclofen can significantly improve reflux symptoms and pH-monitoring and manometry findings to different degrees in all four mentioned categories; although its effect on pH-monitoring parameters seems less significant than the other parameters. Mild neurological and mental status deterioration were the most reported side effects. However, side effects occurred in a portion of less than 5% of short-term users and nearly 20% of long-term users.

Conclusion

In PPI-resistant patients, a trial of adding baclofen to the PPI may be helpful. Baclofen therapies may be more beneficial for symptomatic GERD patients who also report concurrent conditions including alcohol use disorder, non-acid reflux, or obesity.

Systematic review registration

https://clinicaltrials.gov/.

Association between sociodemographic characteristics and knowledge and practice of COVID-19 measures among households in Mombasa and Kilifi County, Kenya

BACKGROUND

Coronavirus disease 2019 (COVID-19), declared a global pandemic by the World Health Organization (WHO), is a severe acute respiratory disease. The Kenyan Ministry of Health (MoH) put in place measures that included mandatory face masking, hand and cough hygiene and social and physical distancing to reduce disease transmission and increase prevention efforts. The primary objective of this study was to determine how sociodemographic characteristics affect knowledge and practice of the above measures.

METHODS

A cross-sectional study was conducted to assess water, sanitation and hygiene practices for the prevention and control of COVID-19 in Kilifi and Mombasa Counties, Kenya. Data collection was accomplished through a mobile data collection tool. Principal component analysis was used to create a wealth index using data on asset ownership and housing characteristics. Bloom cut-off points of 80-100%, 60-79% and ≤59% were used to determine knowledge and practice.

RESULTS

Of the 612 households, 339 (55.4%) were from Kilifi County and 273 (44.6%) were from Mombasa County. A total of 431 (70.4%) were female and the mean age of the household members was 38.2±14.8 y.Almost all (99.2%) respondents were aware of COVID-19, with 60% knowing prevention, symptoms and persons at a higher risk of contracting the virus. Females had the highest knowledge of COVID-19 and were likely to practice prevention and control measures, unlike males. Age was significant (p<0.05) with knowledge and practice.

CONCLUSIONS

The sociodemographic characteristics of populations play a key role in behavioural aspects as far as prevention and control of COVID-19 are concerned. There is a need for partnerships between the MoH and county governments to put in place a multisectoral community approach to advance feasible behavioural interventions among targeted populations towards combating the spread of COVID-19.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Assessment of water, sanitation and hygiene practices for prevention and control of COVID-19 in Kenya

Background

Safely managed water, sanitation and hygiene (WASH) services are an essential part of preventing and protecting human health during infectious disease outbreaks, including the current coronavirus disease 2019 (COVID-19) pandemic. Additionally, adherence to COVID-19 measures, including washing hands using soap and proper waste disposal, no doubt can improve containment of the virus.

Methods

A cross-sectional survey was conducted in Kilifi and Mombasa Counties in Kenya. A total of 612 quantitative data were collected using a mobile data collection tool Open Data Kit. Parametric and non-parametric tests were used to examine factors associated with WASH practices and control of COVID-19 in Kenya.

Results

More than half of the respondents were from Kilifi, 431 (70.4%) were female and the mean age was 38.2±14.8 y. Households in Kilifi were most likely not to have enough water, while Mombasa households were more likely to pay for water. Sanitation coverage was 47.6%, with more than half sharing sanitation facilities. Sharing of latrines was significantly associated with county and income level. Accessing soap was worse compared with the month prior to the survey, only 3.9% had their garbage collected by formal service providers and only 17% reported wearing any protective gear while handling waste at home.

Conclusions

Water is disproportionately available in the two counties, with low sanitation coverage. There is low knowledge on hand washing and inadequate waste disposal services.

Phenotypic and Genotypic Characteristics of Methicillin-Resistant Staphylococcus aureus Isolated from Dairy and Meat Products in Iran

Background: Methicillin-Resistant Staphylococcus aureus (MRSA) plays an important role in gastrointestinal diseases. The goal of this research was to determine phenotypic and genotypic characteristics of MRSA isolated from dairy and meat products in Iran. Methods: Ninety-three S. aureus isolates were prepared which had been obtained in our previous study. Antimicrobial susceptibility testing was done using disk diffusion method. The isolates were further analyzed by mecA gene detection. Staphylococcal Enterotoxins (SEs) and Toxic Shock Syndrome Toxin 1 (TSST1) were screened. Biotyping and molecular typing were done by short sequence repeats of spa and coa genes. Results: Five out of 93 S. aureus isolates (5.37%) included mecA. All five MRSA isolates were sensitive to at least six tested antibiotics and none were resistant to vancomycin. Furthermore, two isolates were multidrug resistant. Four isolates produced SEs and TSST1. Three out of 5 isolates were related to human biotype and two belonged to non-host-specific biotype. Conclusion: Presence of MRSA in dairy and meat products may be an important hygienic risk for the Iranian consumers, especially for immunocompromised people.

A combined panel of circulating microRNA as a diagnostic tool for detection of the non-small cell lung cancer

BACKGROUND

Recently, much attention has been paid to use circulating microRNAs (miRs) as a non-invasive tumor marker. The present study for the first time was designed to evaluate concurrent use of miR-21, miR-638, miR148 and miR-152 as putative diagnostic tool for detection of non-small cell lung carcinoma (NSCLC).

METHODS

Forty-three patients diagnosed as primary NSCLC was included in this study. The level of selected miRs was measured in whole blood specimens of patients and controls. The corresponding values were also obtained in stages I-IV. We also assessed possible correlation between selected miRs and the clinicopathological findings of studied individuals.

RESULTS

miR-21 was increased in patients compared to controls (P = 0.004). In contrast, circulating miR-638, miR-148 and miR-152 was observed to be down-regulated in NSCLC patients than controls (P = 0.001, 0.003, 0.053, respectively). Rise in miR-21-5p expression and decreased blood level of miR-148a-3p was associated with higher stage of NSCLC. The highest sensitivity (90%) was observed for miR-21 while miR-148 had the highest specificity (71%). The corresponding sensitivity and specificity for combined-miRs-panel was 96.4% and 86.67%, respectively.

CONCLUSION

In summary, our data suggested the diagnostic importance of combined-miR-panel including miR-21, miR-638, miR148 and miR-152 for effective discrimination of NSCLC from non-cancerous subjects.

Evaluation of 1,25-dihydroxyvitamin D3 pathway in patients with chronic urticaria

BACKGROUND

Previous studies showed the role of vitamin D (Vit D) on the progression of chronic urticaria. To the best of our knowledge, there are no other results regarding the contribution of single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) and vitamin D binding protein (VDBP) genes in chronic urticaria (CU).

AIM

In the present study, we investigated the Vit pathway and the association between VDR and VDBP gene polymorphisms and CU risk in Iranian population.

METHODS

All participating individuals in the present study were evaluated for serum Vit D and VDBP concentration VDR rs1544410 and rs2228570 and VDBP rs7041using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. The associations of studied analytes and three SNPs with clinical and laboratory outcomes were investigated in CU patients.

RESULTS

Patients with CU showed lower Vit D compared to controls (19.26 ± 1.26 vs. 31.72 ± 7.14 ng/ml, P-value = 0.006). There was a significant correlation between Vit D levels and urticaria activity score. Serum VDBP was significantly higher in CU patients than controls (1317.3 ± 183.71 vs. 395.77 ± 12.96 µg/ml, P-value <0.0001) and had a positive correlation to progression of CU. The A allele of this polymorphism might be a potential risk factor for progression of CU [odds ratio 4.3434, 95% confidence interval (1.7331-10.8852), Z-statistic = 3.133, P-value = 0.0017].

CONCLUSION

In summary, this study demonstrated that change in Vit D pathway in the level of gene or protein may be a risk factor for progression of CU.

Inhibitory effect of Lactobacillus plantarum and Lb. fermentum isolated from the faeces of healthy infants against nonfermentative bacteria causing nosocomial infections

Nosocomial infection constitutes a major public health problem worldwide. Increasing antibiotic resistance of pathogens associated with nosocomial infections has also become a major therapeutic challenge for physicians. Thus, development of alternative treatment protocols, such as the use of probiotics, matters. The aim of this research was to determine the antagonistic properties of Lactobacillus plantarum and Lb. fermentum isolated from the faeces of healthy infants against nonfermentative bacteria causing nosocomial infections. One hundred five samples of nosocomial infections were collected and processed for bacterial isolation and antimicrobial susceptibility testing following standard bacteriologic techniques. The antibiotic susceptibility test was performed by the disk diffusion method, and antagonistic effect of Lactobacillus strains was investigated by well diffusion method. Of 105 samples, a total of 29 bacterial strains were identified as nonfermentative bacteria, including 17 Acinetobacter baumannii and 12 Pseudomonas aeruginosa. A. baumannii showed high resistance to tested antibiotics except ampicillin/sulbactam, and P. aeruginosa showed resistance to ampicillin/sulbactam and gentamicin and sensitive to amikacin and meropenem. Lb. plantarum had antagonistic properties against both A. baumannii and P. aeruginosa strains. Lb. plantarum had considerable effects on preventing the growth of A. baumannii and P. aeruginosa strains. However, further research is needed to better understanding of these effects on P. aeruginosa.

Dissipative Optomechanical Preparation of Macroscopic Quantum Superposition States

The transition from quantum to classical physics remains an intensely debated question even though it has been investigated for more than a century. Further clarifications could be obtained by preparing macroscopic objects in spatial quantum superpositions and proposals for generating such states for nanomechanical devices either in a transient or a probabilistic fashion have been put forward. Here, we introduce a method to deterministically obtain spatial superpositions of arbitrary lifetime via dissipative state preparation. In our approach, we engineer a double-well potential for the motion of the mechanical element and drive it towards the ground state, which shows the desired spatial superposition, via optomechanical sideband cooling. We propose a specific implementation based on a superconducting circuit coupled to the mechanical motion of a lithium-decorated monolayer graphene sheet, introduce a method to verify the mechanical state by coupling it to a superconducting qubit, and discuss its prospects for testing collapse models for the quantum to classical transition.

A Lumped Parameter Method to Calculate the Effect of Internal Carotid Artery Occlusion on Anterior Cerebral Artery Pressure Waveform

BACKGROUND AND OBJECTIVE

Numerical modeling of biological structures would be very helpful tool to analyze hundreds of human body phenomena and also diseases diagnosis. One physiologic phenomenon is blood circulatory system and heart hemodynamic performance that can be simulated by utilizing lumped method. In this study, we can predict hemodynamic behavior of one artery of circulatory system (anterior cerebral artery) when disease such as internal carotid artery occlusion is occurred.

METHOD

Pressure-flow simulation is one the leading common approaches for modeling of circulatory system behavior and forecasts of hemodynamic in numerous physiological conditions. In this paper, by using lumped model (electrical analogy), CV system is simulated in MATLAB software (SIMULINK environment).

RESULTS

The performance of healthy blood circulation and heart is modeled and the obtained results used for further analyses. The stenosis of internal carotid artery at different rates was, then, induced in the circuit and the effects are studied. In stenosis cases, the effects of internal carotid artery occlusion on  left anterior cerebral artery pressure waveform are investigated.

CONCLUSION

The findings of this study may have implications not only for understanding the behavior of human biological system at healthy condition but also for diagnosis of diseases in circulatory and cardiovascular system of human body.

New insight to IL-23/IL-17 axis in Iranian infected adult patients with gastritis: effects of genes polymorphisms on expression of cytokines

BACKGROUND AND OBJECTIVE

Chronic inflammation is the hallmark of the pathogenesis of H. pylori-induced gastric cancer. IL-17A and IL-17F are inflammatory cytokines expressed by a novel subset of CD4+Th cells and play critical function in inflammation. We evaluated the relationship between IL-17A G197A, IL-17F A7488G and IL23R+2199 A/C polymorphisms with IL-6, IL-17, IL-21, IL-23 and TGF-β1 mRNAs expression in regard to H. pylori infection with chronic gastritis.

MATERIAL AND METHODS

Total RNA and genomic DNA were extracted from gastric biopsies of 58 H. pylori-infected patient with gastritis. Afterward, mucosal IL-6, IL-17, IL-21, IL-23 and TGF-β1 mRNAs expression and polymorphisms in IL-17A G197A, IL-17F A7488G and IL-23R +2199A/Cin gastric biopsies were determined by real-time PCR and PCR-RFLP.

RESULTS

Our results show that IL-17A G197A, IL-17F A7488G andIL23R +2199A/C polymorphisms have no effect on mucosal expression of IL-6, IL-17, IL-21 and TGF-β1 mRNAs expression in H. pylori-infected patients with chronic gastritis.

CONCLUSIONS

These results suggest that IL-17A G197A, IL-17F A7488G and IL23R +2199A/C polymorphisms no alter mucosal cytokine pattern in Iranian patients with H. pylori-associated gastritis diseases.

MODELING THE HEART BEAT, CIRCLE OF WILLIS AND RELATED CEREBRAL STENOSIS USING AN EQUIVALENT ELECTRONIC CIRCUIT

In this study, the cardiovascular system is modeled using an equivalent electronic system focusing on the circle of Willis (COW). COW supports adequate blood supply to the brain. Each cardiovascular artery is modeled using electrical elements such as resistor, capacitor and inductor. MATLAB Simulink software was used to obtain the left and right ventricles pressure as well as pressure distribution at efferent arteries of the COW. Firstly, the normal operation of the system was shown then the stenosis of cerebral arteries was induced in the circuit and the effects were studied. In the normal condition, the difference between pressure distribution of right and left efferent arteries (left and right anterior cerebral arteries (ACA-A2), left and right middle cerebral arteries (MCA), left and right posterior cerebral arteries (PCA-P2) was calculated to see the effect of anatomical difference between left and right sides of supplying arteries of COW. In stenosis cases, the effect of internal carotid artery (ICA) occlusion on efferent arteries pressure was investigated. The model results were verified by comparing to the clinical observation reported in the literature.

Modeling of cerebral aneurysm using equivalent electrical circuit (Lumped Model)

The circle of Willis (CoW) is a key asset in brain performance as it supports adequate blood supply to the brain. The lumped method (electrical equivalent circuits) is a useful model to simulate the process of the human cardiovascular system. In this study, the whole cardiovascular system is modeled, using an equivalent electrical circuit to investigate an aneurysm in an artery. The cerebrovascular system consists of 29 compartments, which includes the CoW. Each vessel is modeled by a resistor, a capacitor and an inductor. Using MATLAB Simulink, the left and right ventricles are modeled by controlled voltage sources and diodes. The effects of the left internal carotid artery aneurysm (Fusiform) on the pressure of the efferent arteries in the circle of Willis are studied. The modeling results are entirely in agreement with the available clinical observations. The results of the present study may have clinical implications for modeling different cardiovascular diseases, such as arterial stiffness and atherosclerosis.

Entanglement swapping with local certification: application to remote micromechanical resonators

We propose a protocol for entanglement swapping which involves tripartite systems. The generation of remote entanglement induced by the Bell measurement can be easily certified by additional local measurements. We illustrate the protocol in the case of continuous variable systems where the certification is effective for an appropriate class of three-mode gaussian states. We then apply the protocol to optomechanical systems, showing how mechanical entanglement between two remote micromechanical resonators can be generated and certified via local optical measurements.

Reversible optical-to-microwave quantum interface

We describe a reversible quantum interface between an optical and a microwave field using a hybrid device based on their common interaction with a micromechanical resonator in a superconducting circuit. We show that, by employing state-of-the-art optoelectromechanical devices, one can realize an effective source of (bright) two-mode squeezing with an optical idler (signal) and a microwave signal, which can be used for high-fidelity transfer of quantum states between optical and microwave fields by means of continuous variable teleportation.

Absorbed dose assessment of cardiac and other tissues around the cardiovascular system in brachytherapy with 90Sr/90Y source by Monte Carlo simulation

Cardiac disease is one of the most important causes of death in the world. Coronary artery stenosis is a very common cardiac disease. Intravascular brachytherapy (IVBT) is one of the radiotherapy methods which have been used recently in coronary artery radiation therapy for the treatment of restenosis. (90)Sr/(90)Y, a beta-emitting source, is a proper option for cardiovascular brachytherapy. In this research, a Monte Carlo simulation was done to calculate dosimetry parameters and effective equivalent doses to the heart and its surrounding tissues during IVBT. The results of this study were compared with the published experimental data and other simulations performed by different programs but with the same source of radiation. A very good agreement was found between results of this work and the published data. An assessment of the risk for cardiac and other sensitive soft tissues surrounding the treated vessel during (90)Sr/(90)Y IVBT was also performed in the study.

The Impact of Bone Marrow Transplantation on Sexual Functioning and it’s Relation to Depression and Anxiety

Aims:

The aim of this study was to investigate the prevalence of sexual dysfunctions and its relationship with depression and anxiety in a sample of patients underwent bone marrow transplantation (BMT).

Methods:

A cross-sectional study was conducted in 135 married patients who underwent BMT at least 1 year before evaluation. Sexual dysfunctions assessed by a questionnaire that was derived from Sexual History Form and Sexual Problem Measure. Hospital Anxiety and Depression Scale (HADS) was used to assess depression and anxiety in patients.

Results:

Questionnaires were completed by 128 (82.5%) participant. Fifty three percents of participants was male. The mean age of participants was 39.57±8.74. Sexual dysfunctions in post BMT period were significantly more frequent than period prior to the beginning of oncologic malignancy (P< 0.05). Sexual activity was decreased significantly after BMT (P< 0.01). The three most prevalent sexual dysfunctions in male group were premature ejaculation(56%) and problem in orgasm(40%) and desire(32.7%), and in female group were problem in arousal(77%) and desire(77%) and painful intercourse(77%). Sexual dysfunction was more prevalent in female group.

According to HADS score, 42(32.8%) patients had clinical depression (HADS-D score>14) and 12 (9.8%) patients had clinical anxiety (HADS-A score>14). There was not any significant relationship between mean HADS-A and HADS-D scores and scores of sexual dysfunctions questionnaires.

Conclusion:

This study showed that sexual function and activity may be adversely affected by BMT. Factors other than anxiety and depression may have correlation with sexual dysfunction in these patients, of course limitation of this study should be considered.

Buckling of adaptive elastic bone-plate: theoretical and numerical investigation

During day-to-day activities, many bones in the axial and appendicular skeleton are subjected to repetitive, cyclic loading that often results directly in an increased risk of bone fracture. In clinical orthopedics, trabecular fatigue fractures are observed as compressive stress fractures in the proximal femur, vertebrae, calcaneus and tibia, that are often preceded by buckling and bending of microstructural elements (Müller et al. in J Biomechanics 31:150 1998; Gibson in J Biomechanics 18:317-328 1985; Gibson and Ashby in Cellular solids 1997; Lotz et al. in Osteoporos Int 5:252-261 1995; Carter and Hayes in Science 194:1174-1176 1976). However, the relative importance of bone density and architecture in the etiology of these fractures are poorly understood and consequently not investigated from a biomechanical point of view. In the present contribution, an attempt is made to formulate a bone-plate buckling theory using Cowin's concepts of adaptive elasticity (Cowin and Hegedus in J Elast 6:313-325 1976; Hegedus and Cowin J Elast 6:337-352 1976). In particular, the buckling problem of a Kirchhoff-Love bone plate is investigated numerically by using the finite difference method and an iterative solving approach (Chen in Comput Methods Appl Mech Eng 167:91-99 1998; Hildebland in Introduction to numerical analysis 1974; Richtmyer and Morton in Difference methods for initial-value problems 1967).

Propriétés mécaniques de greffons humains provenant de têtes fémorales et traitées par un procédé d’épuration physico-chimique (Ostéopure™)

PURPOSE OF THE STUDY

Bone grafts and bone substitutes must be biocompatible osteoconductors with satisfactory mechanical properties similar to native bone. When the bone treatment is conducted under specific conditions, the elasticity module under infra-maximal loading can be optimized to achieve reproducible values. The purpose of this work was to determine the effect of the cleaning and sterilization process using Osteopure on the biomechanical properties of trabecular bone harvested from human femoral heads.

MATERIAL AND METHOD

Seventy trabecular bone samples were tested: group 1F (fresh samples); group 1N (after application of Osteopure cleaning); group 1S (after Osteopure cleaning and sterilization). Non-destructive and destructive tests (group 1D) were performed. Two fresh femoral heads were used as controls for the destructive test (group 2). The first non-destructive test was applied directly after section (group 1F). Other samples were then purified with Osteopure treatment and a second non-destructive test was conducted (group 1N). A third non-destructive test was conducted after sterilization with 25 kgray radiation (group 1S). Treatments 1 and 2 were performed by OST Developpement SA (Clermont-Ferrand). Finally a destruction test was applied along the directional axis (group 1D). For the 31 samples in group 2 (control) the destructive test was applied along the directional axis immediately after section. Compression tests were performed at a deformation speed of 3 mm/min for 0.3% deformation.

RESULTS

The Young module did not exhibit any significant difference between the three steps of the testing in the three orthogonal directions. The Young module was not significantly different between group 1F and group 2 (controls). Maximal force of compression was significantly different (P<0.01). There was a linear relationship between maximal force at rupture and the Young module obtained during destructive tests, for groups 1D and 2 respectively. The compression curves obtained from sterilized samples (group 1D) were not significantly different from those observed for fresh trabecular bone in group 2 (controls).

DISCUSSION

The Young module values measured from 70-673 MPa. For non-destructive tests, the module values were to the order of 64% of those obtained for destructive tests. Decreased maximal force of rupture observed for treated samples in comparison with fresh samples can be explained by the extraction of most of the lipids.

CONCLUSION

The Osteopure method does not alter stiffness of bone allografts. The elasticity module observed in treated bones is close to that observed in fresh bones. Mechanical resistance to compression is however only half the force of compression observed in the hip joint for daily activities. The linear relationship between the elasticity mode and loading required for rupture is not affected by treatment with Osteopure. The advantages related to elimination of prions or viral contamination appear by far to be more important than the minor changes observed in the mechanical characteristics of allografts.

Cholera in Indonesia in 1993-1999

Cholera-specific surveillance in Indonesia was initiated to identify the introduction of the newly recognized Vibrio cholerae non-O1, O139 serotype. Findings from seven years (1993-1999) of surveillance efforts also yielded regional profiles of the importance of cholera in both epidemic and sporadic diarrheal disease occurrence throughout the archipelago. A two-fold surveillance strategy was pursued involving 1) outbreak investigations, and 2) hospital-based case recognition. Rectal swabs were transported to Jakarta for culture and isolates were characterized by serotypic identification. Outbreak findings showed that V. cholerae O1, Ogawa serotype, was the predominant etiology in all 17 instances of investigated epidemic transmission. Monitoring of eight hospitals representing seven provinces provided 6,882 specimens, of which 9% were culture positive for V. cholerae: 589 (9%) for O1 and 20 (< 1%) for non-O1 strains. Proportional representation of V. cholerae O1 among cases of sporadic diarrheal illness was variable, ranging from 13% in Jakarta to < 1% in Batam. Overall, 98% of V. cholerae O1 cases were the Ogawa serotype. There was no instance of non-O1, O139 serotype introduction in either epidemic or sporadic disease form. Anti-microbial drug susceptibility was consistently demonstrated, both temporally and spatially, except against colistin. Evidence is provided that epidemic and sporadic cholera occurrence in western Indonesia is associated with periods of low rainfall. Conversely, in the more eastern portion of the country, heavy rainfall may have contributed to epidemic cholera transmission.

Phospholipid molecular species distribution of some medically important Candida species analysed by fast atom bombardment mass spectroscopy

The aim of this study was to obtain detailed information on phospholipids (PL) of the medically important Candida species and to determine their possible chemotaxonomic significance. Lipids were extracted from 22 strains representing 8 Candida species and their PL molecular species distributions were determined by Fast Atom Bombardment Mass Spectroscopy (FAB MS) in negative ion mode. Fifteen major lower mass peaks (m/z 221 to 289) were attributable to the expected presence of carboxylate anions and 24 major higher mass peaks (m/z 557 to 837) were attributable to phospholipid anions. Major carboxylate peaks were of the following m/z and identities : 253, C16:1; 255, C16:0; 277, C18:3; 279, C18:2; 281, C18:1; and 283, C18:0. The most abundant peaks consistent with the presence of phospholipid molecular species anions include those of m/z 673, 743, 833, 834 and 836 tentatively identified as phosphatidic acid (PA) (34:1), phosphatidylglycerol (PG) (34:3), phosphtidylinositol (PI) (34:2) and two unknown molecular species. This profile is diagnostic for the genus Candida. Quantitative differences were observed between different Candida species. Thus, polar lipid molecular species distribution in Candida spp. has chemotaxonomic significance, especially so in the case of carboxylate anions.

Phospholipid analogue distribution in Capnocytophaga

Polar lipids of nineteen previously characterised culture collection strains of Capnocytophaga were analysed using fast atom bombardment mass spectrometry (FAB MS) in negative mode. All strains examined had a major peak at m/z 241, consistent with the expected presence of the pentadecanoate anion. The most intense higher mass anions, consistent with expected presence of phospholipid molecular species, were as follows: m/z 574, 588, 618 and 662 which are consistent with presence of PE(24:2), PE(25:2), PE(27:1) and PE(30:0) respectively. Other anions putatively identified as phospholipid anions were: m/z 572, 578, 592, 602, 604, 616 and 720 consistent with presence of PE(24:3), PE(24:0), PE(25:0), PE(26:2), PE(26:1), PE(27:2) and OH-PE(33:0). Capnocytophaga isolates share a distinctive phospholipid fingerprint which appears to lack the somewhat higher mass phospholipid analogues observed in related oral bacteria. Within the genus, the profiles obtained showed only quantitative differences which did not correlate with previous studies.

Nuclear magnetic resonance spectroscopic and principal components analysis investigations into biochemical effects of three model hepatotoxins

1H NMR spectroscopy of urine combined with pattern recognition (PR) methods of data analysis has been used to investigate the time-related biochemical changes induced in Sprague-Dawley rats by three model hepatotoxins: alpha-naphthyl isothiocyanate (ANIT), d-(+)-galactosamine (GalN), and butylated hydroxytoluene (BHT). The development of hepatic lesions was monitored by conventional plasma analysis and liver histopathology. Urine was collected continuously postdosing up to 144 h and analyzed by 600-MHz 1H NMR spectroscopy. NMR spectra of the urine samples showed a number of time-dependent perturbations of endogenous metabolite levels that were characteristic for each hepatotoxin. Biochemical changes common to all three hepatotoxins included a reduction in the urinary excretion of citrate and 2-oxoglutarate and an increased excretion of taurine and creatine. Increased urinary excretion of betaine, urocanic acid, tyrosine, threonine, and glutamate was characteristic of GalN toxicity. Both GalN and ANIT caused increased urinary excretion of bile acids, while glycosuria was evident in BHT- and ANIT-treated rats. Data reduction of the NMR spectra into 256 integrated regions was used to further analyze the data. Mean values of each integrated region were analyzed by principal components analysis (PCA). Each toxin gave a unique time-related metabolic trajectory that could be visualized in two-dimensional PCA maps and in which the maximum distance from the control point corresponded to the time of greatest cellular injury (confirmed by conventional toxicological tests). Thereafter, the metabolic trajectories changed direction and moved back toward the control region of the PR map during the postdose recovery phase. The combination of urinary metabolites which were significantly altered at various time points allowed for differentiation between biliary and parenchymal injury. This NMR-PR approach to the noninvasive detection of liver lesions will be of value in furthering the understanding of hepatotoxic mechanisms and assisting in the discovery of novel biomarkers of hepatotoxicity.

Phospholipid profiles in the oral yeast Candida

Individual molecular species of phospholipids can now be readily detected using fast atom-bombardment mass spectrometry (FAB MS). The aim was to obtain detailed information on individual molecular species of Candida phospholipids using FAB MS. Lipids were extracted from Candida isolates and prepared for FAB MS analysis in negative-ion mode. Each isolate yielded several hundred anion peaks. The major anion peaks consistent with the presence of phospholipids included those of mass/charge (m/z) 836, 743, 715, 744 and 834 tentatively identified as phosphatidylethanolamine PE(43:5), phosphatidylglycerol PG(34:3), PG(32:3), PE(36:1) and PE(43:5). Major peaks consistent with the presence of carboxylate anions were of m/z 241, 253, 255, 277, 279, 281, 283, and 307 putatively identified as C15:0, C16:1, C18:3, C18:2, C18:1, C18:0 and C20:2 which also support the putative identifications of phospholipids. Such phospholipid profiles differ from those published for other microorganisms analysed by FAB MS. Quantitative differences were observed between different candidal species. Candida albicans may be readily differentiated from C. glabrata on the basis of its carboxylate anions. Within species, there are quantitative differences in phospholipid profiles. Thus, Candida has a unique combination of phospholipid analogues with potential chemosystematic significance.

[Low back pain and headache during immediate postpartum. Role of obstetrical epidural analgesia]

The rate of low back pain and headache following parturition seems to be higher in patients delivered under epidural analgesia. The aim of this study, performed in the immediate postpartum (up to 3rd day) and including 200 patients delivered vaginally, was to assess the incidence and the risk factors of low back pain and headache. A total of 31.5% of them complained of low back pain (LBP+) after parturition. They were significantly younger than those without low back pain (LBP-) (p < 0.03) and have had significantly more often epidural analgesia (p < 0.05). However, there were no statistically significant differences concerning weight, weight gain, parity, duration of labour and duration of epidural analgesia. The LBP+ patients complained significantly more often of cervical (p < 0.04) and low back pain (p < 0.02) during pregnancy, than the LBP-. In the immediate postpartum period, cervical and dorsal pain as well as headache occurred significantly more often in LBP+ than in LBP+ (p < 0.001). The intensity of low back pain during pregnancy (p < 0.006). Risk factors for postpartum LBP were epidural analgesia (OR = odds ratio = 6.59), LBP (OR = 6.50) and cervical pain (OR = 2.75) during pregnancy. The influence of epidural analgesia is questionable, as there was no difference between duration of labour and duration of epidural analgesia, if used, between the two groups. Patients for whom epidural analgesia was required are probably more susceptible to pain during pregnancy. Patients who suffered from postpartum headache (PPHDA+) were comparable to those who did not (PPDHA-).(ABSTRACT TRUNCATED AT 250 WORDS)