In this research work, the nanostructured Fe-Mn (BM0), Fe-Mn-Cu (BM1), Fe-Mn-W (BM2), and Fe-Mn-Co (BM3) biodegradable alloys were successfully synthesized using mechanical alloying. The microstructure of the synthesized alloys was examined using XRD, SEM equipped with EDS, and HRTEM techniques. The results obtained based on these techniques confirmed the development of nanostructured BM0, BM1, BM2, and BM3 alloys and homogenous solid solutions with an even elemental dispersion. The compressibility of the synthesized alloys was investigated experimentally and empirically in the as-milled conditions and after applying a stress relief treatment (150 °C for 1 h). The load applied for compaction experiments ranged from 25–1100 MPa with a rate of 1 mm/min. According to the experimentation performed in the current study, the relative density of the as-milled BM0, BM1, BM2, and BM3 alloys was 72.90% and 71.64%, 72.32%, and 72.03%, respectively. After applying the stress relief treatment, the density was observed to increase to 75.23%, 77.10%, 72.65%, and 72.86% for BM0-S, BM1-S, BM2-S and BM3-S samples, respectively. A number of compaction models were tested to identify the optimum models for predicting the compressibility behavior of nanostructured Fe-Mn, Fe-Mn-Cu, Fe-Mn-W, and Fe-Mn-Co alloys in the as-milled and stress-relieved conditions. 相似文献
Restless legs syndrome [RLS] is known as a disease of iron and dopaminergic dysregulation but inflammatory processes might also have a role in the pathogenesis. In this study, we compared the circulating levels of hsCRP, IL-1β, IL-6, and TNF-α in patients with primary restless legs syndrome [RLS] and healthy control subjects.
Methods
We prospectively included 29 patients with primary RLS and 65 healthy controls [HC], all age-sex matched. The diagnosis of RLS was established using international guidelines. IRLSSG Severity Scale was used to evaluate the severity of RLS. Plasma levels of hsCRP, IL-1β, IL-6, and TNF-α were measured in all participants.
Results
The mean age of patients was 37.8?±?11.3 and 52% of RLS group were women. Serum IL-1β, IL-6, and TNF-α levels of the patient group were statistically significantly higher compared to HC [p?<?0.001 for all variables]. Plasma levels of hsCRP did not differ between groups. There were 8 patients with mild RLS [28%], 13 patients with moderate RLS [45%], and 8 patients with severe RLS [28%]. Only IL-6 values were significantly different between the groups. In the severe group, the value of IL-6 was significantly higher than in the other groups [p: 0.03].
Conclusion
These results showing higher circulating levels of inflammatory cytokines in patients with RLS support the notion that inflammation may be involved in the pathogenesis of primary RLS. However, it is necessary to perform further studies to determine if this finding is a cause or an effect.
Chlorotoxin is a small 36 amino-acid peptide identified from the venom of the scorpion Leiurus quinquestriatus. Initially, chlorotoxin was used as a pharmacological tool to characterize chloride channels. While studying glioma-specific chloride currents, it was soon discovered that chlorotoxin possesses targeting properties towards cancer cells including glioma, melanoma, small cell lung carcinoma, neuroblastoma and medulloblastoma. The investigation of the mechanism of action of chlorotoxin has been challenging because its cell surface receptor target remains under questioning since two other receptors have been claimed besides chloride channels. Efforts on chlorotoxin-based applications focused on producing analogues helpful for glioma diagnosis, imaging and treatment. These efforts are welcome since gliomas are very aggressive brain cancers, close to impossible to cure with the current therapeutic arsenal. Among all the chlorotoxin-based strategies, the most promising one to enhance patient mean survival time appears to be the use of chlorotoxin as a targeting agent for the delivery of anti-tumor agents. Finally, the discovery of chlorotoxin has led to the screening of other scorpion venoms to identify chlorotoxin-like peptides. So far several new candidates have been identified. Only detailed research and clinical investigations will tell us if they share the same anti-tumor potential as chlorotoxin. 相似文献
In recent years, research and development of geopolymers has gained significant interest in the fields of repairs and restoration. This paper investigates the application of a geopolymer as a repair material by implementation of high-calcium fly ash (FA) as a main precursor, activated by a sodium hydroxide and sodium silicate solution. Three methods of concrete substrate surface preparation were cast and patched: as-cast against ordinary Portland cement concrete (OPCC), with drilled holes, wire-brushed, and left as-cast against the OPCC grade 30. This study indicated that FA-based geopolymer repair materials (GRMs) possessed very high bonding strength at early stages and that the behavior was not affected significantly by high surface treatment roughness. In addition, the investigations using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy have revealed that the geopolymer repair material became chemically bonded to the OPC concrete substrate, due to the formation of a C–A–S–H gel. Fundamentally, the geopolymer network is composed of tetrahedral anions (SiO4)4− and (AlO4)5− sharing the oxygen, which requires positive ions such as Na+, K+, Li+, Ca2+, Na+, Ba2+, NH4+, and H3O+. The availability of calcium hydroxide (Ca(OH)2) at the surface of the OPCC substrate, which was rich in calcium ions (Ca2+), reacted with the geopolymer; this compensated the electron vacancies of the framework cavities at the bonding zone between the GRM and the OPCC substrate. 相似文献
Obstructive coronary artery disease (OCAD) and coronary slow flow (CSF) are frequent angiographic findings for patients that have chest pain and require frequent hospital admission. The retina provides a window for detecting changes in microvasculature relating to the development of cardiovascular diseases such as arterial hypertension or coronary heart disease.
Objectives
To assess the coronary and ocular circulations in patients with CSF and those with obstructive coronary artery disease.
Methods
A prospective study was conducted over 3.5?years, included a total of 105 subjects classified to 4 groups: Group I (OCAD): Included 30 patients with obstructive coronary artery disease, group II (CSF): Included 30 patients with coronary slow-flow, group III (Control 1): Included 30 healthy control persons and group IV (Control 2): Included 15 patients indicated for coronary angiography that proved normal. All participants were subjected to coronary angiography (except control group 1), ophthalmic artery Doppler for measuring Pulsatility index (PI) and resistivity index (RI) and Fluorescence angiography of retinal vessels.
Results
Patients with CSF showed slow flow retinal circulation (microcirculation) evidenced by prolonged fluorescein angiography (Arm-retina time [ART] & Arterio-venous Transit time [AVTT]). Ophthalmic artery Doppler measurements (RI & PI) were significantly delayed in OCAD and CSF patients. There was significant positive correlation between TIMI frame count in all subjects and ART, AVTT, PI, RI and Body Mass Index. Using ART cutoff value of >16?s predicted CSF with sensitivity and specificity of 100%, meanwhile AVTT of >2?s predicted CSF with a sensitivity 96.7% and specificity of 93.3.
Conclusion
Both delayed arm-retina time and retinal arterio-venous transit times can accurately predict coronary slow-flow. 相似文献
Background: Pancreaticoduodenectomy(PD) is the standard curative treatment for periampullary tumors. The aim of this study is to report the incidence and predictors of long-term survival( ≥ 5 years) after PD. Methods: This study included patients who underwent PD for pathologically proven periampullary adenocarcinomas. Patients were divided into 2 groups: group(I) patients who survived less than 5 years and group(II) patients who survived ≥ 5 years. Results: There were 47(20.6%) long-term survivors( ≥ 5 years) among 228 patients underwent PD for periampullary adenocarcinoma. Patients with ampullary adenocarcinoma represented 31(66.0%) of the long-term survivors. Primary analysis showed that favourable factors for long-term survival include age 60 years old, serum CEA 5 ng/mL, serum CA 19-9 37 U/mL, non-cirrhotic liver, tumor size 2 cm, site of primary tumor, postoperative pancreatic fistula, R0 resection, postoperative chemotherapy, and no recurrence. Multivariate analysis demonstrated that CA 19-9 37 U/mL [OR(95% CI) = 1.712(1.24 8–2.34 8), P = 0.001], smaller tumor size [OR(95% CI) = 1.335(1.032–1.726), P = 0.028] and R0 resection [OR(95% CI) = 3.098(2.095–4.582), P 0.001] were independent factors for survival ≥ 5 years. The prognosis was best for ampullary adenocarcinoma, for which the median survival was 54 months and 5-year survival rate was 39.0%, and the poorest was pancreatic head adenocarcinoma, for which the median survival was 27 months and 5-year survival rate was 7%. Conclusions: The majority of long-term survivors after PD for periampullary adenocarcinoma are patients with ampullary tumor. CA 19-9 37 U/mL, smaller tumor size, and R0 resection were found to be independent factors for long-term survival ≥ 5 years. 相似文献
This study aimed to investigate the prevalence of pregnancy experience and its association with contraceptive knowledge among single adults in a low socio-economic suburban community in Kuala Lumpur, Malaysia.
Methods
A cross-sectional survey was conducted in 2012 among the Kerinchi suburban community. Of the total 3,716 individuals surveyed, young single adults between 18 and 35 years old were questioned with regard to their experience with unplanned pregnancy before marriage. Contraceptive knowledge was assessed by a series of questions on identification of method types and the affectivity of condoms for the prevention of sexually transmitted diseases.
Results
A total of 226 female and 257 male participants completed the survey. In total, eight female (3.5%) participants reported experience with an unplanned pregnancy before marriage, and five male (1.9 %) participants had the experience of impregnating their partners. The participants had a mean total score of 3.15 (SD = 1.55) for contraceptive knowledge out of a possible maximum score of five. Female participants who had experienced an unplanned pregnancy had a significantly lower contraceptive knowledge score (2.10 ± 1.48) than who had never experienced pregnancy (3.30 ± 1.35), p<0.05. Likewise, male participants who had experienced impregnating their partners had a significantly lower contraceptive knowledge score (1.60 ± 1.50) than those who did not have such experience (3.02 ± 1.59), p<0.05.
Conclusion
The results showed evidence of premarital unplanned pregnancy among this suburban community. The low level of contraceptive knowledge found in this study indicates the need for educational strategies designed to improve contraceptive knowledge.
The breast cancer survival rate is the highest among all types of cancers, and survivors returning to work after completing treatment is extremely important in regards to economy and rehabilitation. The aim of this systematic review study is to identify the prevalence of breast cancer survivors who return to work (RTW) and the factors associated to RTW.
Methods
A computer based literature search was carried out. "PubMed, Cochrane Library, Embase, Web of Science, and Science Direct" databases were searched systematically. Our search strategy identified a total of 12,116 papers of which 26 studies met the inclusion criteria and quality assessment. These were original papers published between January 2003 and January 2013.
Results
The trends in RTW differ among countries for the breast cancer survivors. The time to RTW after successful cancer treatment also varies among the countries and by ethnicity. The prevalence of the RTW varies from 43% to 93% within one year of diagnosis. The prevalence of the RTW for the Netherland is the lowest in the world (43%). The United States survivors showed the highest RTW (93%) within 12 months of the diagnosis. Numerous barriers and facilitators were identified as factors that affect RTW. For instance, socio-demographic factors such as education and ethnicity; treatment oriented factors such as chemotherapy; work related factors such as heavy physical work; disease related factors such as poor health condition and fatigue; and psychological factors such as depression and emotional distress, act as barriers of RTW. In contrast, social, family, employer support, and financial independency emerge as key facilitators in enabling breast cancer survivors to return and continue work.
Conclusion
Minimising these identified barriers and strengthening these facilitators could further improve the work condition and increase the percentage of RTW among the breast cancer survivors.