21 research outputs found
Graded cellular structures for enhanced performance of additively manufactured orthopaedic implants
Hip implants face a significant challenge due to their limited lifespan, a concern amplified by the rising human life expectancy. Lattice structures have demonstrated the ability to provide precise control over geometry, thereby significantly enhancing implant performance. This paper introduces the development of graded additively manufactured Ti6Al4V lattice structures for orthopaedic implants. The objective focuses on developing a graded lattice unit cell design mirroring human bone properties, emphasising high surface curvature and design versatility to improve mechanical and biomedical properties, specifically osseointegration and stress shielding. The study involves modelling and grading simple cubic (SC) and body-centred cubic (BCC) lattice structures with various geometries and graded conditions and conducting compressive tests to identify the optimal configuration. The results showed that filleting was found to be the mechanical strength. On the other hand, BCC lattice structures demonstrated superior performance compared to SC structures. The optimised structure with a pore size of 400 ”m provided an elastic modulus of 15.7 GPa, yield strength of 296 MPa and compressive strength of 530 MPa. This graded lattice design approach provides a promising technique for enhancing hip implant performance, offering potential improvements
Chemical studies of chromanone-thiadiazole, pyridazine and thiosulfin hybrid
3-Chlorochromanon derivatives 4a,b are reacted with hydrazine hydrate to afford 3-hydrazino-2-tetrahydro(pyran or thiopyran)chroman-4-ones 5a,b. Then compound 5a,b is reacted with carbon disulfide and acetylacetone to give 5'-thiolo - 2-tetrahydro(pyrane or thiopyran)- spiro[chroman-3,2'- [1,3,4]-thiadiazole]-4-one 6a,b and 3', 5'-dimethyl- 2-tetrahydro(pyran or thiopyran) spiro [chroman-3,2'- piprazine]-4-one 7a,b, respectively. α-Chlorosulfenyl chlorides 2a,b are treated with thioacetic acid to form α-chloroalkyl disulfides 8a,b, the latter compounds 8a,b were treated with morpholine to furnish a mixture of 1,3,4-oxadithiins 9a,b, 1,3,4,5,6-oxatetrathiocins 10a,b, 1,2,4-trithiolanes 11a,b (cis- and trans-), 1,2,4,5-tetrathiins (cis- and trans-) 12a,b. The formation of the new compounds are confirmed by spectral (IR, 1H NMR, and MS) analysis
Derivatization and biological activity studies of 3-chloro-3-chlorosulfenyl spiro tetrahydropyran/tetrahydrothiopyran-4,2'-chroman-4'-one
1502-1510The adducts 4a,b-7a,b have been obtained either by reducing α-chloro-ÎČ-oxosulfenyl chlorides 2a,b with iodide
ion in the presence of dienes namely, 2-methyl-1,3-butadiene (isoperene), 2,3-dimethyl-1,3-butadiene, 1,2,3,4-
tetrachlorocyclopentadiene, or 1,3-cyclohexadiene, respectively; or by thermolysis of oxadithiin derivatives 3a,b in the
presence of the same aforementioned dienes presumably via the formation of the same intermediate A in both cases of
compounds 2a,b and 3a,b. It is observed that α-chloro-ÎČ-oxosulfenyl chlorides 2a,b undergo straight forward substitution
with potassium cyanide to give 8a,b. Direct oxidation of 2a,b with H2O2/AcOH affords 3,3-dichloropyran-4-ones 9a,b,
while conversion of 2a,b to the sulfonamides 10a,b followed by oxidation provides 3-chloropyranones 11a,b. Antioxidant
and antimicrobial evaluation of compounds 4a,b-6a,b shows moderate activiy. MIC of the derivative 6b reveals a
remarkable inhibition of the pathogenic gram positive bacteria (Staphylococcus aureus ) as well as gram negative E coli
Derivatization and biological activity studies of 3-chloro-3-chlorosulfenyl spiro tetrahydropyran/tetrahydrothiopyran-4,2'-chroman-4'-oneÂ
The adducts 4a,b-7a,b have been obtained either by reducing α-chloro-ÎČ-oxosulfenyl chlorides 2a,b with iodide ion in the presence of dienes namely, 2-methyl-1,3-butadiene (isoperene), 2,3-dimethyl-1,3-butadiene, 1,2,3,4-tetrachlorocyclopentadiene, or 1,3-cyclohexadiene, respectively; or by thermolysis of oxadithiin derivatives 3a,b in the presence of the same aforementioned dienes presumably via the formation of the same intermediate A in both cases of compounds 2a,b and 3a,b. It is observed that α-chloro-ÎČ-oxosulfenyl chlorides 2a,b undergo straight forward substitution with potassium cyanide to give 8a,b. Direct oxidation of 2a,b with H2O2/AcOH affords 3,3-dichloropyran-4-ones 9a,b, while conversion of 2a,b to the sulfonamides 10a,b followed by oxidation provides 3-chloropyranones 11a,b. Antioxidant and antimicrobial evaluation of compounds 4a,b-6a,b shows moderate activiy. MIC of the derivative 6b reveals a remarkable inhibition of the pathogenic gram positive bacteria (Staphylococcus aureus ) as well as gram negative E coli.
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study
Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.
Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.
Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05â2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001).
Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
Chemical studies of chromanone-thiadiazole, pyridazine and thiosulfin hybrid
230-2363-Chlorochromanon derivatives 4a,b are reacted with hydrazine hydrate to afford 3-hydrazino-2-tetrahydro(pyran or
thiopyran)chroman-4-ones 5a,b. Then compound 5a,b is reacted with carbon disulfide and acetylacetone to give 5'-thiolo -
2-tetrahydro(pyrane or thiopyran)- spiro[chroman-3,2'- [1,3,4]-thiadiazole]-4-one 6a,b and 3', 5'-dimethyl- 2-
tetrahydro(pyran or thiopyran) spiro [chroman-3,2'- piprazine]-4-one 7a,b, respectively. α-Chlorosulfenyl chlorides 2a,b are
treated with thioacetic acid to form α-chloroalkyl disulfides 8a,b, the latter compounds 8a,b were treated with morpholine to
furnish a mixture of 1,3,4-oxadithiins 9a,b, 1,3,4,5,6-oxatetrathiocins 10a,b, 1,2,4-trithiolanes 11a,b (cis- and trans-),
1,2,4,5-tetrathiins (cis- and trans-) 12a,b. The formation of the new compounds are confirmed by spectral (IR, 1H NMR, and
MS) analysis
Coping Strategies in Egyptian Ladies with Breast Cancer
Introduction A diagnosis of breast cancer regardless of the stage can be stressful, impact multiple spheres of life, and disrupt physical status, emotional and spiritual well-being, and personal relationships for the patient and family. In order to adapt, the patient ought to employ certain coping mechanisms. Individuals with terminal illness who utilize coping strategies have better quality of life compared to those who do not. Patients and Methods This study aimed to determine the strategies used by females with breast cancer to cope with such stress by using Brief COPE scale and the hospital anxiety and depression scale. The study included 56 female patients diagnosed with operable breast cancer at Mansoura Oncology Center before surgery. Results Large proportion of patients used acceptance, religion, and emotional support in coping with the stress of having breast cancer. Patients with depressive symptoms scored significantly higher venting while those with anxiety scored higher positive reframing, planning, and venting. Conclusion Efforts should be made to encourage women with breast cancer to use coping strategies that have been found to be helpful (eg, acceptance, emotional support, distraction, and active coping strategies)
Cabergoline versus calcium infusion in the prevention of ovarian hyperstimulation syndrome: a randomised controlled study
The aim of this study was to compare the efficacy of calcium infusion versus cabergoline in the prevention of ovarian hyperstimulation syndrome (OHSS) in IVF patients at high risk for OHSS. One hundred and seventy patients who were stimulated using the long luteal GnRH agonist protocol and at high risk for developing OHSS were randomised in a 1:1 ratio to cabergoline group and calcium gluconate group. In cabergoline group, 0.5âmg of cabergoline was administered once daily p.o. for eight days starting on the day of HCG administration. In calcium gluconate group, intravenous calcium gluconate (10%, 10âml in 200âml of physiologic saline) was administered daily for four days starting on the day of ovum pickup. Six patients in cabergoline group and eight patients in calcium gluconate group developed moderate OHSS. One patient in each group developed severe OHSS. The incidence of moderate/severe OHSS was comparable between both groups (8.24% vs. 10.59%, p valueââ=ââ.599, ORâ=â0.76, 95% CI [0.269â2.138]). The implantation, clinical and ongoing pregnancy rates were similar in the two groups (16.91% vs. 15.84%, pâ=â.771, 35.29% vs. 32.94%, pâ=â.746, and 30.59% vs. 28.24%, pâ=â.736, respectively). In conclusion, calcium infusion and cabergoline have comparable effectiveness in the prevention of OHSS. Both drugs are well tolerated, cheap and have no adverse effects on the reproductive outcomes of IVF cycle. Clinical trial registration: The trial was registered on clinical trials.gov database [NCT02875587].Impact Statement What is already known on this subject? The effectiveness of cabergoline in the prevention of OHSS in IVF patients at high risk for OHSS is confirmed by overwhelming scientific evidence. Calcium infusion is a novel strategy for prevention of OHSS. Few studies reported the use of calcium infusion in the prevention of OHSS. A retrospective study and a randomised controlled study revealed that calcium infusion reduces the incidence of OHSS. Moreover, a quasi-randomised study revealed that calcium infusion is as effective as cabergoline in the prevention of OHSS. What the results of this study add? Calcium infusion and cabergoline have comparable effectiveness in the prevention of OHSS. Both drugs are well tolerated, cheap and have no adverse effects on the reproductive outcomes of IVF cycle. What the implications are of these findings for clinical practice and/or further research? Calcium infusion should be used to minimise the incidence of OHSS in IVF patients at high risk for OHSS