The evolution of bilaterally symmetric feathers is a fundamental process leading toward flight. One major unsolved mystery is how the feathers of a single bird can form radially symmetric downy feathers and bilaterally symmetric flight feathers. In developing downy feather follicles, barb ridges are organized parallel to the long axis of the feather follicle. In developing flight-feather follic...

BACKGROUND Cervical pedicle screw (CPS) insertion is a technically demanding procedure. The quantitative understanding of cervical pedicle morphology, especially the narrowest part of cervical pedicle or isthmus, would minimize the risk of catastrophic damage to surrounding neurovascular structures and improve surgical outcome. The aim of this study was to investigate morphology and quantify co...

OBJECTIVE To compare the von Mises stresses of the internal fixation devices among different short segment pedicle screw fixation techniques to treat thoracic 12 vertebral fractures, especially the mono-segment pedicle screw fixation and intermediate unilateral pedicle screw fixation techniques. METHODS Finite element methods were utilised to investigate the biomechanical comparison of the fo...

Wheat (Triticum aestivum, Triticum durum) grains were excised immediately following fertilization and cultured until maturity. A rachis fragment attached to the grain was required to ensure an increase in grain size for the first 10 days following fertilization. A (14)C-labeling study revealed that 8-day-old grains accumulated more dry matter into the ethanol-insoluble fraction when grown on ag...

OBJECTIVE A variety of different pedicle screws entry point techniques are used for the lumbar pedicle screws placement. This study reported Kim's entry point of lumbar pedicle screws with free hand technique and the accuracy of this technique. METHODS We retrospectively reviewed the 584 cases with free hand placed lumbar pedicle screw placement. The diagnosis included 491 cases with degenera...

Cervical pedicle screw has been shown to provide stronger fixation than other methods. Due to these virtue of biomechanical characteristic, pedicle screw fixation can be used in a wide range of cervical spinal disorders, and excellent clinical results have been reported. However, this procedure is technically demanding because of the great variation in pedicle dimension and angulations between ...

About 12,000 years ago in the Near East, humans began the transition from hunter-gathering to agriculture-based societies. Barley was a founder crop in this process, and the most important steps in its domestication were mutations in two adjacent, dominant, and complementary genes, through which grains were retained on the inflorescence at maturity, enabling effective harvesting. Independent re...

OBJECTIVE To present the accuracy and safety of cervical pedicle screw insertion using the technique with direct exposure of the pedicle by laminoforaminotomy. METHODS We retrospectively reviewed 12 consecutive patients. A total of 104 subaxial cervical pedicle screws in 12 patients had been inserted. We also assessed the clinical and radiological outcomes and analyzed the direction and grade...

While the biomechanical properties of pedicle screws have proven to be superior in the lumbar spine, little is known concerning pullout strength of pedicle screws in comparison to hooks in the thoracic spine. In vitro biomechanical pullout testing was performed to evaluate the axial pullout strength of pedicle screws versus pedicle and laminar hooks in the thoracic spine with regard to surgical...

vaginal leiomyomas are uncommon benign tumour with variable clinical presentation. these tumours arise most commonly from anterior vaginal wall. we report a case of 50-year old postmenopausal woman who presented with urinary retention, profuse vaginal bleeding and mass protruding into vagina. local examination revealed a pedunculated mass attached to the posterior vaginal wall with vascular sta...