For the mechanical joining of aviation-grade aluminum alloys, the study introduces an innovative approach using self-punching lockbolts. This method involves the utilization of a profiled collar and ...a specially designed bolt to seamlessly join EN AW-2024 T42 aluminum sheets, up to a thickness of 8.0 mm, without the need for pre-holes. In this process, when the aluminum sheets are punched, the collar undergoes slight deformation, effectively functioning as a die. Subsequently, the collar is systematically formed by applying increased force. By fine-tuning the design of the bolt ring groove, it becomes feasible to create a joint with a bolt length that accommodates sheet thickness variations of up to 1.6 mm. To facilitate this development, the joining process was meticulously designed and the auxiliary part was optimized with the aid of numeric simulation tools. The process simulation enabled the identification of deformation mechanisms within the collar, accounting for both geometry and material properties. The important factors influencing collar deformation include collar thickness, shoulder height, and shoulder diameter. Furthermore, experimental investigations were conducted to assess the mechanical properties of the joint and evaluate how material-specific factors influence joint failure behavior. It can be seen that the formation of the mechanical fit is influenced by the ring groove depth and the fitting position. The joints failed under shear tensile load exclusively at the bolt head.
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•An innovative mechanical joining technology designed specifically for the aviation industry.•Pre-hole-free joining of aluminum sheets up to 8 mm with process-specific auxiliary joining elements.•Process-integrated punching of the joining partners using the auxiliary joining elements.•One bolt geometry designed to accommodate various sheet thicknesses.•Characterization of the mechanical properties of the optimized joints.
Hidradenitis suppurativa (HS) rarely affects pediatric patients. The literature on pediatric HS patients is scarce. This is a cross-sectional study based on case note review or interviews and ...clinical examination of 140 pediatric patients undergoing secondary or tertiary level care. Patients were predominantly female (75.5%,
n
= 105) with a median age of 16. 39% reported 1st-degree relative with HS. Median BMI percentile was 88, and 11% were smokers (
n
= 15). Median modified Sartorius score was 8.5. Notable comorbidities found were acne (32.8%,
n
= 45)
,
hirsutism (19.3%,
n
= 27), and pilonidal cysts (16.4%,
n
= 23). Resorcinol (
n
= 27) and clindamycin (
n
= 25) were the most frequently used topical treatments. Patients were treated with tetracycline (
n
= 32), or oral clindamycin and rifampicin in combination (
n
= 29). Surgical excision was performed in 18 patients, deroofing in five and incision in seven patients. Obesity seemed to be prominent in the pediatric population and correlated to parent BMI, suggesting a potential for preventive measures for the family. Disease management appeared to be similar to that of adult HS, bearing in mind that the younger the patient, the milder the disease in majority of cases.
The assessment of bird-based welfare indicators plays an important role in the evaluation of bird welfare. The aim of the study was to histologically validate a visual scoring system for hock burn in ...broilers and to detect threshold values of a visual score to define welfare-relevant alterations in terms of mild lesions or ulcers of the hock. We collected 200 hocks of 39- to 42-day-old Ross 308 broilers after the slaughter process. Each hock was scored visually ("macro scores" 0-4) and evaluated histologically ("micro scores" 0-3), with high scores representing more severe lesions. Although we found a tendency for higher micro scores with increasing macro scores, an exact allocation of macro to micro scores was not possible. For example, macro score 1 could represent micro scores 1, 2 and 3, whereas macro scores 3 and 4 always represented micro score 3 (ulcer). The conditional probability of certain micro scores for given macro scores was estimated using a multinomial logistic regression model. Ulcer showed the highest probability at macro score 1, whereas mild lesions were not found to have an estimated highest probability at any macro score. The depth of inflammation of hock burn lesions increased with increasing macro scores up to macro score 3 with an average depth of 1019 µm. Visually more severe and deeper lesions were also histologically rated with higher scores. Thus, considering limitations, the herein validated macroscopic assessment scheme for hock burn allows an estimation of histological alterations in hocks of broilers.
RESEARCH HIGHLIGHTS
Histological validation of a visual assessment scheme for hock burn in broilers.
Tendency for higher micro scores with increasing macro scores.
Estimation of histological score via macro score possible with limitations.
Histological depth of inflammation increased with an increasing macro score.
Homopolymers and block copolymers of higher epoxides (butene oxide and hexene oxide) are synthesized using 1-alkanols and polyethylene glycol monomethyl ether (PEG-MME) 1100 as initiators by anionic ...ring opening polymerization in bulk. Most of the samples were synthesized with controlled microwave heating in sealed vessels. Tri- and tetrablock copolymers with different repeat units in the individual blocks are synthesized by living polymerization with addition of the next monomer after complete consumption of the previous one. The products thus obtained are characterized using size exclusion chromatography (SEC), liquid chromatography under critical conditions (LCCC) and liquid adsorption chromatography (LAC).
An attenuated Plasmodium falciparum (Pf) sporozoite (SPZ) vaccine, PfSPZ Vaccine, is highly protective against controlled human malaria infection (CHMI) 3 weeks after immunization, but the durability ...of protection is unknown. We assessed how vaccine dosage, regimen, and route of administration affected durable protection in malaria-naive adults. After four intravenous immunizations with 2.7 × 10(5) PfSPZ, 6/11 (55%) vaccinated subjects remained without parasitemia following CHMI 21 weeks after immunization. Five non-parasitemic subjects from this dosage group underwent repeat CHMI at 59 weeks, and none developed parasitemia. Although Pf-specific serum antibody levels correlated with protection up to 21-25 weeks after immunization, antibody levels waned substantially by 59 weeks. Pf-specific T cell responses also declined in blood by 59 weeks. To determine whether T cell responses in blood reflected responses in liver, we vaccinated nonhuman primates with PfSPZ Vaccine. Pf-specific interferon-γ-producing CD8 T cells were present at ∼100-fold higher frequencies in liver than in blood. Our findings suggest that PfSPZ Vaccine conferred durable protection to malaria through long-lived tissue-resident T cells and that administration of higher doses may further enhance protection.
A porcine model of osteosarcoma Saalfrank, A; Janssen, K-P; Ravon, M ...
Oncogenesis,
2016-Mar-14, Letnik:
5, Številka:
3
Journal Article
Recenzirano
Odprti dostop
We previously produced pigs with a latent oncogenic TP53 mutation. Humans with TP53 germline mutations are predisposed to a wide spectrum of early-onset cancers, predominantly breast, brain, adrenal ...gland cancer, soft tissue sarcomas and osteosarcomas. Loss of p53 function has been observed in >50% of human cancers. Here we demonstrate that porcine mesenchymal stem cells (MSCs) convert to a transformed phenotype after activation of latent oncogenic TP53(R167H) and KRAS(G12D), and overexpression of MYC promotes tumorigenesis. The process mimics key molecular aspects of human sarcomagenesis. Transformed porcine MSCs exhibit genomic instability, with complex karyotypes, and develop into sarcomas on transplantation into immune-deficient mice. In pigs, heterozygous knockout of TP53 was sufficient for spontaneous osteosarcoma development in older animals, whereas homozygous TP53 knockout resulted in multiple large osteosarcomas in 7-8-month-old animals. This is the first report that engineered mutation of an endogenous tumour-suppressor gene leads to invasive cancer in pigs. Unlike in Trp53 mutant mice, osteosarcoma developed in the long bones and skull, closely recapitulating the human disease. These animals thus promise a model for juvenile osteosarcoma, a relatively uncommon but devastating disease.
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