38 research outputs found

    Application of Variable Compression Ratio VCR Technology in Heavy-Duty Diesel Engine

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    The chapter presents the application of variable compression ratio VCR technology for an internal combustion engine. The engineÔÇÖs overall construction has been designed as the deep reconfiguration of liquid-cooled, heavy-duty diesel engine of type IFA 4 VD 14,5/12-1 SRW. An eccentric shaft-based sliding mechanism has been used for changing position of engine cylinder head assembly. By ensuring a high stiffness of the engine layout together with additional sliding mechanism, the combustion chamber volume of the engine can be changed precisely without changing the displacement of the cylinders. In result, the engine compression ratio can be continuously varied during normal engine operation from the value of 19:1 down to 9:1

    Reappraisal of the variational anatomy of the vermiform appendix and their possible clinical applicability: a cadaveric analysis

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    Background: The anatomical variations in the position, length, arterial supply and extension of mesoappendix of the vermiform appendix (VA) are pivotal to establishing a standard pattern in the study population of known ethnicity and their clinical applicability. Materials and methods: The present study was conducted on 47 adult human cadavers, thirty-five males and twelve female subjects of North Indian ethnicity. Results: Retrocaecal appendix was found in 23 cases (48.9%) followed by pelvic in 13 (27.7%), three cases each of pre-ileal, post-ileal, and promontoric (6.4%), one case (2.1%) each of paracaecal and subcaecal reported. The length of VA varied from three to ten centimetres, averaging about 7.37┬▒1.67 cm, both the shortest (2.9 cm) (female) and longest (10 cm) (male) were of retrocaecal type. The main appendicular artery (MAA) showed a widely varied branching pattern within the mesoappendix, ranging from three to seven. Fourteen cases (29.78%) showed the accessory appendicular artery (AAA) or dual arterial supply, arising from the ileocolic artery in ten (21%) and in four from the post-caecal (9%). In the specimens with dual arterial supply, the estimated portions of the VA supplied by the MAA also vary with distal ┬żth being supplied in 57.14%. In ten cases (21%), the mesoappendix failed to reach the tip of the VF. Conclusions: Knowledge of anatomical diversities in position, length, course, arterial supply, branching pattern, and mesoappendix is potentially crucial in avoiding surgical catastrophes. Atypical positions of the organ can cause diagnostic confusion and result in delayed treatment. VF supplied by an end artery is one of the causes of the occurrence of appendicitis and mesoappendix not reaching the tip making the organ more vulnerable to necrosis. Vascular variations and anomalies involving the main or accessory appendicular artery are critical to prevent haemorrhage or faulty ligatures

    A three-headed piriformis muscle: an anatomical case study and narrative review of literature

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    Introduction: The piriformis muscle (PM) is found in the gluteal region, exiting the pelvis through the greater sciatic foramen and dividing it into the suprapiriform and infrapiriform foramina. The piriformis works as part of the hip external rotator muscle group, and is responsible for rotation of the femur upon hip extension and abduction of the femur during flexion of the hip joint. The aim of the present report is to describe a very rare case of the primary three-headed piriformis muscle. To the best knowledge of the authors, the said variant has not yet been described in the existing literature. Case report: The 71-year-old male formalin-fixed cadaver was subjected to routine dissection. After careful removal of the connecting tissue, three separate, primary heads of the PM were identified. The lower head of the PM arose from the middle part of the sacral bone; 87.56 mm long and 9.73 mm wide. The medial head was attached to the internal part of the posterior inferior iliac spine; 121.6 mm long and 20.97 mm wide. The upper head was attached to the external part of the posterior inferior iliac spine; 78.89 mm long and 23.94 mm wide. All heads converged into a common tendon which inserted onto the greater trochanter. Conclusions: The clinical importance of this work comes down to the fact that the aberrant PM may be the reason behind the piriformis syndrome and its associated symptoms. Moreover, knowledge regarding the variant anatomy of the PM is of immense importance to, e.g., anesthesiologists performing CT- or ultrasound-guided SN injection for local anesthesia, radiologists interpreting imaging studies, and surgeons, especially during posterior approaches to the hip and pelvis

    Bilateral absence of the deep brachial artery

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    The aim of the following study was to present and comprehensively describe a case of a bilateral absence of the DBA. Furthermore, its embryology and clinical significance will also be discussed. During routine dissection, a 71-year-old male cadaver with a bilateral abnormality in the DBA and its branches was found. The first branch of the BA was found to be the radial collateral artery, which passed behind the radial nerve. Furthermore, the middle collateral artery originated distal to the radial collateral artery and gave off first a singular, minor muscular branch and then the superior ulnar collateral artery. Later, the preceding nutrient arteries of the humerus and the deltoid branch consecutively branched off from the middle collateral artery. Subsequently, the middle ulnar collateral artery, the inferior ulnar collateral artery, the deltoid artery, the radial artery, and the ulnar artery branched off from the BA, as adapted in the current knowledge regarding the anatomy of the upper extremity. Furthermore, detailed measurements of the distances between the mentioned arteries were carried out. In the present study, a bilateral absence of the DBA was demonstrated. Meta-analysis focusing on the anatomy of this artery has shown how variable its characteristics are. However, our case report is the first in the literature to present this extremely rare variation. Having adequate knowledge regarding the anatomy of the arteries of the proximal arm is of immense importance when performing orthopedic and reconstructive surgeries in this area

    Thoracolumbar fascia in the lumbar region: anatomical description and topographical relationships to the cutaneous nerves: a preliminary study

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    Background: The study aims to determine principal topographical relations between thoracolumbar fascia (TLF) and lateral branches derived from the dorsal (posterior) rami of lumbar spinal nerves and elucidate their potential link to lumbar region pain. The research protocol involves basic TLF morphological description, evaluating its relation to the nerves, and examining general histology. Materials and methods: The research was conducted on four male cadavers fixed in 10% neutral buffered formalin. Results: The dorsal rami of the spinal nerves branched into medial and lateral divisions. The lateral divisions were about 1 mm thick and mainly visible in the subcutaneous tissue during stratigraphic dissection. They pierced the TLF superficial layer. They descended sidewards and downwards within the superficial fascia (laterally to the erector spinae muscle) to provide sensory innervation to the skin. Conclusions: Anatomical relationships between TLF, deep (intrinsic or true) back muscles, and dorsal rami of the spinal nerves are complex and may be clinically involved in low back pain etiopathogenesis

    Polyorchidism: An Up-to-Date Systematic Review

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    Polyorchidism is a rare male urogenital tract anomaly characterized by at least one supernumerary testis in the scrotum or ectopically. According to data based on our systematic review, 76% of the supernumerary testes (SNTs) were located in the scrotum, and 24% were extra-scrotal (p < 0.001). Among testes located outside the scrotum, 87% were found in the inguinal canal and 13% in the abdominal cavity. In 80% of cases, the diagnosis of SNT was made based on imaging tests, and the remaining 20% of cases were detected incidentally during surgery. The imaging tests performed (US or MRI) resulted in a significantly higher rate of patients who qualified for observation vs. surgical treatment (45% vs. 35%, p < 0.001). The most common conditions associated with SNT were ipsilateral inguinal hernia (15% of cases) and cryptorchidism (15% of cases). Surgery (orchidopexy/orchidectomy) was performed on 54% of patients with SNT, and the decision to observe the SNT was made in a total of 46% of patients (p = 0.001). The therapeutic approach depends on the location of the SNT and the presence of factors that raise suspicion of neoplastic proliferation

    Structural and Metabolic Changes in Bone

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    As an essential component of the skeleton, bone tissue provides solid support for the body and protects vital organs. Bone tissue is a reservoir of calcium, phosphate, and other ions that can be released or stored in a controlled manner to provide constant concentration in body fluids. Normally, bone development or osteogenesis occurs through two ossification processes (intra-articular and intra-chondral), but the first produces woven bone, which is quickly replaced by stronger lamellar bone. Contrary to commonly held misconceptions, bone is a relatively dynamic organ that undergoes significant turnover compared to other organs in the body. Bone metabolism is a dynamic process that involves simultaneous bone formation and resorption, controlled by numerous factors. Bone metabolism comprises the key actions. Skeletal mass, structure, and quality are accrued and maintained throughout life, and the anabolic and catabolic actions are mostly balanced due to the tight regulation of the activity of osteoblasts and osteoclasts. This activity is also provided by circulating hormones and cytokines. Bone tissue remodeling processes are regulated by various biologically active substances secreted by bone tissue cells, namely RANK, RANKL, MMP-1, MMP-9, or type 1 collagen. Bone-derived factors (BDF) influence bone function and metabolism, and pathophysiological conditions lead to bone dysfunction. This work aims to analyze and evaluate the current literature on various local and systemic factors or immune system interactions that can affect bone metabolism and its impairments

    Anatomical and Clinical Aspects of Horseshoe Kidney: A Review of the Current Literature

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    A renal abscess in the isthmus of horseshoe kidney

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    Horseshoe kidney (HSK) is the renal fusion anomaly caused by disturbances in embryonic development when the kidneys are fused together in the lower or upper pole forming an isthmus. The most common disorders in urinary tract related to horseshoe kidney are ureteral pelvic junction obstruction, urinary tract infection and urolithiasis. In our study, we present a rare case of an abscess in the isthmus of horseshoe kidney after extracorporeal shockwave lithotripsy on the right kidney was performed. The patient has had recurrent urolithiasis and underwent 4 treatments on the left kidney in the past without complications
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