Syrian Refugee Relief: A Recent Graduate’s Volunteer Experience

N

Investigation the Coating of Hydroxyapatite on Titanium Substrate by Pulse Laser Deposition

بحثت هذه الدراسة وأعدت طلاء مركب للمزروعات الجراحية باستخدام المواد السيراميكيه النشطه بايولوجيا (bioactive) مثل الهيدروكسيابتايت كطلاءات للمزروعات المعدنيه التي تشجع النمو الطبيعي للعظام عند نقاط التماس بينها وبين العظم الحي. ان الهيدروكسيابتايت (Ca10(PO4)6(OH)2)) او فوسفات الكالسيوم يستخدم كطلاء للمعادن بسبب توافقيته الحياتيه الممتازه كما انه ذو هيكل مشابه للانسجه الصلبه في جسم الانسان. إن تطبيق الطلاء HA على ركائز التيتانيوم أنتجت باستخدام تقنية الترسيب بالليزر النبضي (Pulsed Laser Deposition). في هذا البحث استخدم (HA) كهدف ((Target تم كبسه عند ضغط (150MPa) مع حجم حبيبي مقداره 2.745 µm)) واستخدامه في عملية الطلاء بواسطة تقنية(PLD). أجريت عدة اختبارات لتوصيف طبقة الطلاء مثل XRD وSEM وAFM وEDX لتحديد كمية كلا من الكالسيوم (Ca) والفسفور (P) في طبقة الطلاء. وبعدها تم اختبار الصلاده وخشونة السطح لطبقه الطلاء HA)). تم اجراء اختبار التآكل باستخدام طريقة استكمال منحني تافل في محلول Hank's solution لكل النماذج المطليه وغير المطليه، حيث حصلنا في هذا الاختبار على تحسن كبير في مقاومة التآكل للعينات المطليه عند عدد نبضات 4000 نبضة بمقدار 99.88%.This study investigated and prepared a coating for surgical implants by using hydroxyapatite (HA) empowers characteristic bone that developed at a medium for prosthetic the parts of human body. HA is the generally manufactured from both Calcium (Ca) and Phosphate (P) to produce (Ca10(PO4)6(OH)2) that used as a base material for covering mineral embeds because of its incredible biocompatibility and comparable the synthesis and structure to sclerous tissues of the human body. HA, coatings on titanium substrates have been produced by Pulses laser deposition (PLD) techniques. HA used in this search pressed at pressure (150MPa) with particle size (2.745 µm) and used as a target in coating by (PLD) techniques. Surface characterization studies of the coatings such as XRD, SEM, AFM and EDX to detect the amount of (Ca) and (P) in coating layer were carried out. Then test the micro-hardness, surface roughness for HA coating .Corrosion behavior for uncoated and coated samples with various number of pulses in Hank’s solution by using OCP and the potentially static polarization test were achieved also, , in this test we obtained a greatly improved in corrosion resistance of the samples B1 after coating by 99.88%

Stainless steel top-seat angle beam-to-column connection: Full-scale test and analytical modelling

Stainless steel (SS) is increasingly used for structural applications in the construction industry as its beneficial properties outweigh initial material costs when sustainability aspects and the whole life cycle of structures are appropriately accounted for in the structural design. Despite the well-recognised significance of connections in bare metallic construction, experimental research on SS beam-to-column connections, especially full-scale test results, are scarce. This paper presents a full-scale experimental investigation on the semi-rigid behaviour of top-seat bolted connection (also known as ‘flange cleat’ connection) made from austenitic SS. Deformation characteristics of various elements of the connection were carefully investigated and subsequently used to calibrate nonlinear FE models for parametric analysis. Obtained numerical results were used to develop a four-parameter power model that relies on simplified expressions for key input parameters to predict the semi-rigid behaviour of bolted top-seat connections. Results predicted using the proposed model and those obtained using currently available techniques based on carbon steel behaviour were compared. Outcomes of the current research highlighted the significance of appropriate inclusion of stain hardening offered by austenitic grade to capture the semi-rigid response of such connections

Stateless but rooted: Resistance, land and landscape in the occupied Syrian Golan Heights

Could the struggle against Israeli occupation within this rural vantage on the Middle East offer new insights into the emancipatory potential of agrarian and land-based political movements

Comparing different models of the development of verb inflection in early child Spanish

How children acquire knowledge of verb inflection is a long-standing question in language acquisition research. In the present study, we test the predictions of some current constructivist and generativist accounts of the development of verb inflection by focusing on data from two Spanish-speaking children between the ages of 2;0 and 2;6. The constructivist claim that children's early knowledge of verb inflection is only partially productive is tested by comparing the average number of different inflections per verb in matched samples of child and adult speech. The generativist claim that children's early use of verb inflection is essentially error-free is tested by investigating the rate at which the children made subjectverb agreement errors in different parts of the present tense paradigm. Our results show: 1) that, although even adults ' use of verb inflection in Spanish tends to look somewhat lexically restricted, both children's use of verb inflection was significantly less flexible than that of their caregivers, and 2) that, although the rate at which the two children produced subjectverb agreement errors in their speech was very low, this overall error rate hid a consistent pattern of error in which error rates were substantially higher in low frequency than in high frequency contexts, and substantially higher for low frequency than for high frequency verbs. These results undermine the claim that children's use of verb inflection is fully productive from the earliest observable stages, and are consistent with the constructivist claim that knowledge of verb inflection develops only gradually

Decompressive cervical laminectomy and lateral mass screw-rod arthrodesis. Surgical analysis and outcome

<p>Abstract</p> <p>Background</p> <p>This study evaluates the outcome and complications of decompressive cervical Laminectomy and lateral mass screw fixation in 110 cases treated for variable cervical spine pathologies that included; degenerative disease, trauma, neoplasms, metabolic-inflammatory disorders and congenital anomalies.</p> <p>Methods</p> <p>A retrospective review of total 785 lateral mass screws were placed in patients ages 16-68 years (40 females and 70 males). All cases were performed with a polyaxial screw-rod construct and screws were placed by using Anderson-Sekhon trajectory. Most patients had 12-14-mm length and 3.5 mm diameter screws placed for subaxial and 28-30 for C1 lateral mass. Screw location was assessed by post operative plain x-ray and computed tomography can (CT), besides that; the facet joint, nerve root foramen and foramen transversarium violation were also appraised.</p> <p>Results</p> <p>No patients experienced neural or vascular injury as a result of screw position. Only one patient needed screw repositioning. Six patients experienced superficial wound infection. Fifteen patients had pain around the shoulder of C5 distribution that subsided over the time. No patients developed screw pullouts or symptomatic adjacent segment disease within the period of follow up.</p> <p>Conclusion</p> <p>decompressive cervical spine laminectomy and Lateral mass screw stabilization is a technique that can be used for a variety of cervical spine pathologies with safety and efficiency.</p

Efficacy of a low-cost, inactivated whole-cell oral cholera vaccine: results from 3 years of follow-up of a randomized, controlled trial

BACKGROUND: Killed oral cholera vaccines (OCVs) have been licensed for use in developing countries, but protection conferred by licensed OCVs beyond two years of follow-up has not been demonstrated in randomized, clinical trials. METHODS/PRINCIPAL FINDINGS: We conducted a cluster-randomized, placebo-controlled trial of a two-dose regimen of a low-cost killed whole cell OCV in residents 1 year of age and older living in 3,933 clusters in Kolkata, India. The primary endpoint was culture-proven Vibrio cholerae O1 diarrhea episodes severe enough to require treatment in a health care facility. Of the 66,900 fully dosed individuals (31,932 vaccinees and 34,968 placebo recipients), 38 vaccinees and 128 placebo-recipients developed cholera during three years of follow-up (protective efficacy 66%; one-sided 95%CI lower bound = 53%, p<0.001). Vaccine protection during the third year of follow-up was 65% (one-sided 95%CI lower bound = 44%, p<0.001). Significant protection was evident in the second year of follow-up in children vaccinated at ages 1–4 years and in the third year in older age groups. CONCLUSIONS/SIGNIFICANCE: The killed whole-cell OCV conferred significant protection that was evident in the second year of follow-up in young children and was sustained for at least three years in older age groups. Continued follow-up will be important to establish the vaccine's duration of protection.Dipika Sur ... Stephen Attridge ... et al

Time- and energy-resolved effects in the boron-10 based Multi-Grid and helium-3 based thermal neutron detectors

The boron-10 based Multi-Grid detector is being developed as an alternative to helium-3 based neutron detectors. At the European Spallation Source, the detector will be used for time-of-flight neutron spectroscopy at cold to thermal neutron energies. The objective of this work is to investigate fine time- and energy-resolved effects of the Multi-Grid detector, down to a few $\mu$eV, while comparing it to the performance of a typical helium-3 tube. Furthermore, it is to characterize differences between the detector technologies in terms of internal scattering, as well as the time reconstruction of ~ $\mu$s short neutron pulses. The data were taken at the Helmholtz Zentrum Berlin, where the Multi-Grid detector and a helium-3 tube were installed at the ESS test beamline, V20. Using a Fermi-chopper, the neutron beam of the reactor was chopped into a few tens of $\mu$s wide pulses before reaching the detector, located a few tens of cm downstream. The data of the measurements show an agreement between the derived and calculated neutron detection efficiency curve. The data also provide fine details on the effect of internal scattering, and how it can be reduced. For the first time, the chopper resolution was comparable to the timing resolution of the Multi-Grid detector. This allowed a detailed study of time- and energy resolved effects, as well as a comparison with a typical helium-3 tube.Comment: 37 pages, 21 figure

Invasive Salmonellosis among Children Admitted to a Rural Tanzanian Hospital and a Comparison with Previous Studies

BACKGROUND: The importance of invasive salmonellosis in African children is well recognized but there is inadequate information on these infections. We conducted a fever surveillance study in a Tanzanian rural hospital to estimate the case fraction of invasive salmonellosis among pediatric admissions, examine associations with common co-morbidities and describe its clinical features. We compared our main findings with those from previous studies among children in sub-Saharan Africa. METHODOLOGY/PRINCIPAL FINDINGS: From 1 March 2008 to 28 Feb 2009, 1,502 children were enrolled into the study. We collected clinical information and blood for point of care tests, culture, and diagnosis of malaria and HIV. We analyzed the clinical features on admission and outcome by laboratory-confirmed diagnosis. Pathogenic bacteria were isolated from the blood of 156 (10%) children, of which 14 (9%) were S. typhi, 45 (29%) were NTS and 97 (62%) were other pathogenic bacteria. Invasive salmonellosis accounted for 59/156 (38%) bacteremic children. Children with typhoid fever were significantly older and presented with a longer duration of fever. NTS infections were significantly associated with prior antimalarial treatment, malarial complications and with a high risk for death. CONCLUSIONS/SIGNIFICANCE: Invasive salmonellosis, particularly NTS infection, is an important cause of febrile disease among hospitalized children in our rural Tanzanian setting. Previous studies showed considerable variation in the case fraction of S. typhi and NTS infections. Certain suggestive clinical features (such as older age and long duration of fever for typhoid whereas concomitant malaria, anemia, jaundice and hypoglycemia for NTS infection) may be used to distinguish invasive salmonellosis from other severe febrile illness

In vivo tumor cell adhesion in the pulmonary microvasculature is exclusively mediated by tumor cell - endothelial cell interaction

<p>Abstract</p> <p>Background</p> <p>Metastasis formation is the leading cause of death among colon cancer patients. We established a new in-situ model of in vivo microscopy of the lung to analyse initiating events of metastatic tumor cell adhesion within this typical metastatic target of colon cancer.</p> <p>Methods</p> <p>Anaesthetized CD rats were mechanically ventilated and 10⁶human HT-29LMM and T84 colon cancer cells were injected intracardially as single cell suspensions. Quantitative in vivo microscopy of the lung was performed in 10 minute intervals for a total of 40 minutes beginning with the time of injection.</p> <p>Results</p> <p>After vehicle treatment of HT-29LMM controls 15.2 ± 5.3; 14.2 ± 7.5; 11.4 ± 5.5; and 15.4 ± 6.5 cells/20 microscopic fields were found adherent within the pulmonary microvasculature in each 10 minute interval. Similar numbers were found after injection of the lung metastasis derived T84 cell line and after treatment of HT-29LMM with unspecific mouse control-IgG. Subsequently, HT-29LMM cells were treated with function blocking antibodies against β1-, β4-, and αv-integrins wich also did not impair tumor cell adhesion in the lung. In contrast, after hydrolization of sialylated glycoproteins on the cells' surface by neuraminidase, we observed impairment of tumor cell adhesion by more than 50% (p < 0.05). The same degree of impairment was achieved by inhibition of P- and L-selectins via animal treatment with fucoidan (p < 0.05) and also by inhibition of the Thomson-Friedenreich (TF)-antigen (p < 0.05).</p> <p>Conclusions</p> <p>These results demonstrate that the initial colon cancer cell adhesion in the capillaries of the lung is predominantly mediated by tumor cell - endothelial cell interactions, possibly supported by platelets. In contrast to reports of earlier studies that metastatic tumor cell adhesion occurs through integrin mediated binding of extracellular matrix proteins in liver, in the lung, the continuously lined endothelium appears to be specifically targeted by circulating tumor cells.</p