242 research outputs found
The Biomineralization in Social Wasps (Vespinae): The Presence of Statoliths
In social wasps granular aggregates occur mainly in the head region and the body integument. In the former location they are present both on the outer and inner side of the frons. On the outer side of the frons, in a groove traversing its center, there is a deep pit surrounded by a membrane which forms a cyst-like sac. In the pit of the hornet Vespa orientalis (Linne, 1771), there are aggregates comprising silicon (Sl), potassium (K), calcium (Ca) and iron (Fe), which are arranged in morula-like fashion. A granular material is secreted at the base of sensory hairs (sensilla), distributed on both sides of the groove, as well as along their shafts. Aggregates of sillcon and calcium are also present on the inner side of the frons.
The integumental aggregates are comprised of yellow pigment granules. In the abdominal region these granules, which are concentrated in yellow stripes, assume a quasi-cylindrical shape, measuring 0.6-0.8 ÎĽmin length and 0.3-0.4 ÎĽmin diameter. Their structure is affected by caste, age, exposure to sunlight, and drugs introduced through feeding. Feeding on colchicine induces degeneration of the granules, whereas feeding on xanthines renders them refractory to the destructive action of colchicine. Their main metallic element is K.
We postulate that 1) the granules on both sides of the frons are part of a tympanic and static organ; 2) the yellow granules (YG) dispersed all over the external surface of the body possess properties of organic semiconductors; 3) 1 and 2 are piezoelectric, and are involved both in gravity orientation and transposition from photo to geotaxis
Subcuticular microstructure of the hornet's gaster: Its possible function in thermoregulation
The present study set out to elucidate the structure and function of the large subcuticular air sacs encountered in the gaster of the Oriental hornet Vespa orientalis (Hymenoptera, Vespinae). Gastral segments I, II, III, together with the anterior portion of segment IV, comprise the greater volume of the gaster, and inside them, beneath the cuticle, are contained not only structures that extend throughout their entire length, like the alimentary canal, and the nerve cord with its paired abdominal ganglia, situated near the cuticle in the ventral side, but also the heart, which is actually a muscular and dorsally located blood vessel that pumps blood anteriorly, toward the head of the hornet. The mentioned structures take up only a small volume of the gaster, while the rest is occupied by air sacs and tracheal ducts that also extend longitudinally. Interposed between the two air sacs, there is a hard partition and above it, at the center – a paired tracheal duct that extends the entire length of the air sacs. The endothelium of the air sacs is very anfractuous, thereby enlarging and strengthening the surface area. In each gastral segment there is an aperture for the entry of air, namely, a spiracle. Additionally, in each segment, in the antero-lateral aspect of its tergum and situated between two successive segments, there is an intersegmental conjunctive bearing parallel slits of 1–2 microM in width and 10–30 microM in length. The latter are arranged concentrically around bundles of tracheae that traverse the cuticle from segment to segment. From the upper rims of the slits are suspended downward fringe-like structures or "shutters" ranging between 3–10 microM in length. We discuss the possibility that the Oriental hornet resorts to internal circulation of air, along with a thermoelectric heat pump mechanism, in order to achieve cooling and thermoregulation of its body
Caustic ingestion management: world society of emergency surgery preliminary survey of expert opinion
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Metastatic colorectal cancer to a primary thyroid cancer
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Transformations in the law concerning slavery: legacies of the nineteenth century anti-slavery movement
Acute mesenteric ischemia : guidelines of the World Society of Emergency Surgery
Acute mesenteric ischemia (AMI) is typically defined as a group of diseases characterized by an interruption of the blood supply to varying portions of the small intestine, leading to ischemia and secondary inflammatory changes. If untreated, this process will eventuate in life threatening intestinal necrosis. The incidence is low, estimated at 0.09-0.2% of all acute surgical admissions. Therefore, although the entity is an uncommon cause of abdominal pain, diligence is always required because if untreated, mortality has consistently been reported in the range of 50%. Early diagnosis and timely surgical intervention are the cornerstones of modern treatment and are essential to reduce the high mortality associated with this entity. The advent of endovascular approaches in parallel with modern imaging techniques may provide new options. Thus, we believe that a current position paper from World Society of Emergency Surgery (WSES) is warranted, in order to put forth the most recent and practical recommendations for diagnosis and treatment of AMI. This review will address the concepts of AMI with the aim of focusing on specific areas where early diagnosis and management hold the strongest potential for improving outcomes in this disease process. Some of the key points include the prompt use of CT angiography to establish the diagnosis, evaluation of the potential for revascularization to re-establish blood flow to ischemic bowel, resection of necrotic intestine, and use of damage control techniques when appropriate to allow for re-assessment of bowel viability prior to definitive anastomosis and abdominal closure.Peer reviewe
World society of emergency surgery study group initiative on Timing of Acute Care Surgery classification (TACS).
Timing of surgical intervention is critical for outcomes of patients diagnosed with surgical emergencies. Facing the challenge of multiple patients requiring emergency surgery, or of limited resource availability, the acute care surgeon must triage patients according to their disease process and physiological state. Emergency operations from all surgical disciplines should be scheduled by an agreed time frame that is based on accumulated data of outcomes related to time elapsed from diagnosis to surgery. Although literature exists regarding the optimal timing of various surgical interventions, implementation of protocols for triage of surgical emergencies is lacking. For institutions of a repetitive triage mechanism, further discussion on optimal timing of surgery in diverse surgical emergencies should be encouraged. Standardizing timing of interventions in surgical emergencies will promote clinical investigation as well as a commitment by administrative authorities to proper operating theater provision for acute care surgery
The HNF4A R76W mutation causes atypical dominant Fanconi syndrome in addition to a β cell phenotype
types: JOURNAL ARTICLEMutation specific effects in monogenic disorders are rare. We describe atypical Fanconi syndrome caused by a specific heterozygous mutation in HNF4A. Heterozygous HNF4A mutations cause a beta cell phenotype of neonatal hyperinsulinism with macrosomia and young onset diabetes. Autosomal dominant idiopathic Fanconi syndrome (a renal proximal tubulopathy) is described but no genetic cause has been defined.This article presents independent research supported by the National Institute for Health Research (NIHR) Exeter Clinical Research Facility. The research is funded by a Wellcome Trust Senior Investigator Award, (grant number 098395/Z/12/Z).Wellcome Trus
A Novel Approach to Molecular Recognition Surface of Magnetic Nanoparticles Based on Host–Guest Effect
A novel route has been developed to prepared β-cyclodextrin (β-CD) functionalized magnetic nanoparticles (MNPs). The MNPs were first modified with monotosyl-poly(ethylene glycol) (PEG) silane and then tosyl units were displaced by amino-β-CD through the nucleophilic substitution reaction. The monotosyl-PEG silane was synthesized by modifying a PEG diol to form the corresponding monotosyl-PEG, followed by a reaction with 3-isocyanatopropyltriethoxysilane (IPTS). The success of the synthesis of the monotosyl-PEG silane was confirmed with1H NMR and Fourier transform infrared (FTIR) spectroscopy. The analysis of FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the immobilization of β-CD onto MNPs. Transmission electron microscopy (TEM) indicated that the β-CD functionalized MNPs were mostly present as individual nonclustered units in water. The number of β-CD molecules immobilized on each MNP was about 240 according to the thermogravimetric analysis (TGA) results. The as-prepared β-CD functionalized MNPs were used to detect dopamine with the assistance of a magnet
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