Detection system of the lobster eye telescope with large field of view.

The lobster eye telescope is promising for large-field x ray imaging in astronomy. The special structure of the lobster eye system makes the focal plane a sphere, resulting in detector defocus when the field is large. In this study, we established a model based on the principle of lobster eye imaging and simulated the imaging at different image distances. The results reveal the relationship between the defocus and position accuracy and angular resolution. To ensure the optical performance of the large field lobster eye telescope, we propose a detection system design method using multiple detectors stitched together to form a spherical-like surface and apply it to the development of the Einstein Probe/wide-field x ray telescope (EP/WXT) submodule. About 70% of the detection area is out of focus within 0.5 mm. The scanning image of the integrated WXT submodule shows good uniformity of the point spread function (PSF) for various incident angles, and the effect of defocus on imaging is acceptable.

FastPixN, a new integrated pixel chip for a future fast version of the IRSN - recoil proton telescope.

A first prototype of recoil proton telescope (RPT) is currently working at the AMANDE facility, being developed as a collaboration between IPHC Strasbourg and the LNE-IRSN. The device, able to measure both energy and fluence of neutron fields in the range of 5-20 MeV, has to be improved further, in order to reduce the considerable inelastic background generated by the neutrons inside the RPT itself. To achieve faster running cycles, the present complementary metal-oxide-semiconductor pixels used for proton tracking are to be replaced by a new integrated chip, specially developed for this application. The authors present a first version of this new element, with individual pixels readout at a 200-MHz frequency, with a fast 4-bit ADC for each column of 64 pixels. The measured performances point to a complete frame treatment in only 12.6 µs. With a readout speed multiplied by a factor 400 over the existing device, the authors expect a considerable improvement of the telescope at AMANDE, with the potential to reach neutron fluence rates up to 10(7) n cm(-2) s(-1) or more.

A life course approach to injury prevention: a "lens and telescope" conceptual model.

BACKGROUND: Although life course epidemiology is increasingly employed to conceptualize the determinants of health, the implications of this approach for strategies to reduce the burden of injuries have received little recognition to date. METHODS: The authors reviewed core injury concepts and the principles of the life course approach. Based on this understanding, a conceptual model was developed, to provide a holistic view of the mechanisms that underlie the accumulation of injury risk and their consequences over the life course. RESULTS: A "lens and telescope" model is proposed that particularly draws on (a) the extended temporal dimension inherent in the life course approach, with links between exposures and outcomes that span many years, or even generations, and (b) an ecological perspective, according to which the contexts in which individuals live are critical, as are changes in those contexts over time. CONCLUSIONS: By explicitly examining longer-term, intergenerational and ecological perspectives, life course concepts can inform and strengthen traditional approaches to injury prevention and control that have a strong focus on proximal factors. The model proposed also serves as a tool to identify intervention strategies that have co-benefits for other areas of health.

Postoperative Neurogenic Blepharoptosis after Repair of a Medial Orbital Wall Fracture Using the Transcaruncular Approach

PURPOSE: We report a case of neurogenic blepharoptosis after reconstruction of a medial orbital wall fracture using the transcaruncular approach. CASE SUMMARY: A 13-year-old girl presented with left eyeball pain and binocular diplopia caused by trauma from falling. Orbital computerized tomography showed a blowout fracture of the left medial orbital wall, herniation of the orbital soft tissue into the ethmoid sinus, and a portion of the medial rectus muscle trapped in the fracture. The patient underwent successful reconstruction of the medial orbital wall using the transcaruncular approach. However, moderate blepharoptosis with functional loss of the levator palpebrae superioris muscle developed immediately after awaking from the anesthesia. The blepharoptosis was presumed to have developed due to postoperative edema; therefore, oral corticosteroid was prescribed. However, the blepharoptosis did not improve. No other ocular signs or symptoms were detected. Because neither the margin reflex distance (MRD1) nor the function of the levator palpebrae superioris muscle recovered after eight weeks of conservative treatment, surgical correction of blepharoptosis was performed under local anesthesia. The preaponeurotic fat, soft tissue, tarsal plate, and aponeurosis of the levator palpebrae superioris all appeared normal. The patient underwent maximal resection of the levator palpebrae superioris muscle and the blepharoptosis was alleviated two weeks after the operation.

Surgical Results of Intraoperative Adjustable Suture Strabismus Surgery under Local Anesthesia

PURPOSE: We assessed the postoperative surgical results of intraoperative adjustment technique under topical and subconjunctival anesthesia in children and adult strabismus patients. METHODS: 48 patients (55 cases) who underwent intraoperative adjustable strabismus surgery under topical and subconjunctival local anesthesia in Pusan National University Hospital between the years 2001 and 2004 were examined retrospectively. The deviations preoperatively, at postop. 1 day, 1 month, 3 months and last follow up were measured and follow up period ranged from 3 months to 39 months, average 7.5 months. Success was defined as alignment of overcorrection within 5delta and undercorrection within 10delta at horizontal strabismus, and as alignment within 5delta at vertical strabismus. RESULTS: Of the 48 patients identified (20 men and 28 women; mean age: 29.6 years), 28 had exotropia, 9 had esotropia, 4 had vertical strabismus, and 7 had both horizontal and vertical strabismus. The success rates for exotropia were 84.8% at postop. 3 months and 81.8% at last follow up and 81.8% for esotropia respectively and 72.7% for vertical strabismus respectively. Mean change in the angle of deviation between postoperative 1 day and last follow up was 5.3delta for cases of exotropia, 2.4delta for esotropia and 1.8delta for hypertropia. The visual acuity, preoperative deviation, amount of adjustment, number of operated muscles, and monocular or binocular strabismus surgery had no statistically significant influence on the surgical outcome and change of deviation. CONCLUSIONS: Intraoperative adjustable suture strabismus surgery under topical and subconjunctival local anesthesia had relatively successful results. Postoperative drift toward the original deviation was observed.

Atypical Vogt-Koyanagi-Harada Syndrome in a 7-Year-Old Boy

PURPOSE: Vogt-Koyanagi-Harada syndrome is more common in adults than in children. We report a atypical case of Vogt-Koyanagi-Harada syndrome like white dot syndromes in a 7-year-old child. METHODS: A 7-year-old child visited with complaints of decreased binocular visual acuity. Under ophthalmologic examination, anterior uveitis and optic neuropathy were found. But there was no other retinal lesion. After high-dose intravenous corticosteroids pulse therapy, yellow pigment lesions like white dot syndromes developed in peripheral retina and enlarged without serous retinal detachment. RESULTS: In 5 months after high-dose intravenous corticosteroids pulse therapy, anterior inflammation was decreased and visual acuity was 0.8 in both eyes. But depigmented retinal lesions were increased and sunset glow occurred. Alopecia and poliosis of hair were found. Human leukocyte antigen typings revealed HLA-DR4 antigen.

The Value of Diagnostic Laparoscopy for Assessment of Resectability in Hepatobiliary and Pancreatic Malignancy under the Local Anesthesia / 한국간담췌외과학회지

BACKGROUNDS: Despite the advance of radiologic imaging techniques, not a fewer number of patients with hepatobiliary and pancreatic malignancies are found to be unresectable just at the time of laparotomy. The aim of this study was to evaluate the accuracy of diagnostic laparoscopy for assessing resectability of hepatobiliary and pancreatic malignancies. METHODS: From May 1999 to March 2000, diagnostic laparoscopy was performed in 16 patients with suspected hepatobiliary and pancreatic malignancies after clinical examination, laboratory tests, and radiologic imaging techniques(ultrasonography, computed tomography, ERCP, and PTC). Local anesthesia with intravenous sedation was used. A 10-mm infraumbilical port was used for the telescope and another 5-mm port was used for the working instrument depending upon intra-abdominal findings. During the procedure, we tried to find any evidence of distant metastasis or advanced local invasion such as, peritoneal seeding, metastatic nodule at the liver, major vascular involvement or invasion of adjacent other intraabdominal organ. RESULTS: 4 of 16 patients were found to have unresectable malignancies because of peritoneal seeding, hepatic metastases or ascites by diagnostic laparoscopy. 3 patients had invasion to superior mesenteric vein and adjacent structures overlooked at diagnostic laparoscopy. Sensitivity, specificity, and overall accuracy for assessing resectability were 66.7%, 28.6% and 50.0% for radiologic imaging techniques and 100%, 57.1% and 81.3% for diagnostic laparoscopy. CONCLUSION: Diagnostic laparoscopy under local anesthesia proved to be an effective diagnostic tool for assessing resectability of hepatobiliary and pancreatic malignancies by means of assisting the radiologic imaging technique.

Acute Phase Retinal Phototoxicity Induced by Blue Fluorescent Light / 영남의대학술지

Even though phototherapy is an effective means of treating hyperbilirubinemia, adequate binocular shields are essential to prevent light hazard of retina during phototherapy. The phototherapy to young albino rabbits was performed under various conditions; exposured for 12, 24, and 48 hours, continuity or intermittence of irradiation, and use of shields. Although there was no definite pathologic change in indirect ophthalmoscopic examination, severe damage was seen at electron microscopic level. In all experimental groups, swelling and edema of photoreceptor were seen. at right after phototherapy. Futhermore, more severe damage was seen in case of intermittent irradiated group and prolong exposed group. In mydriatic eyes, severity of damage was similiar to non mydi iatic eyes, but area of retinal damage was more extensive than non-mydriatic eves.. In control group which was protected by binocular shields during phototherapy, no significant abnormality was found.

Effects of Total Hypophys Ectomy on the Blood Sugar and Pancreas in the Dog

Early attempts at determining the effects of experimental ablation of the hypophysis in the mammal resulted ambiguously, for the animals usually died from attendant injury to the brain or form infection, or , if they survived, some of the effects observed often were due to injury to the adjacent regions of the brain during the operation. In 1912, Aschner performed removal of the pituitary body by a transbuccal transsphenoidal route in the dog. Smith in 1927 and 1930 reported two methods of hypophysectomy in the rat; the first one was temporal approach, in this method he exposed the pituitary and destroyed with chromic acid injection; the second one was parapharyngeal route. In 1963, Falconi and Rossi described transauricular hypophysectomy in the rat and mice. It is well known that in studying the effects of hypophysectomy removal of the pituitary must be essentially complete without injury to the adjacent regions of the brain, especially in the hypothalamus. The present study was undertaken to device a method of total hypophysectomy and observe the effects on pancreatic structure and carbohydrate metabolism. In this study twenty adult mongrel dogs, weighting from 7 to 10 kg, were used. Twelve of them were male and eight were female. Operative procedure: Under pentobarbital sodium, 30 mg/kg body weight, intravenous anesthesia the dog was placed on the operating table in prone position, and a tube was inserted in the mouth to displace the mandibular angle anterodownwardly. A vertical incision from the midline to just behind the mandibular angle was made, the temporal muscles were also incised vertically and retracted to expose the temporal bone. Following wide craniectomy down to the base of middle cranial fossa and careful opening the dura, temporal lobe was elevated with about 1cm wide brain retractor at the tip of the middle cranial fossa. Since this approach was deep and narrow, a brilliant illumination was thrown from head lamp at neat the center of the binocular magnifier. As the third cranial nerve and intracranial portion of the internal carotid artery were exposed, arachnoid membrane was torn and aspirated cerebrospinal fluid slowly to obtain wider exposure, then elevated posterior communicating artery to expose the pituitary body and stalk. The stalk was clipped and sectioned then pituitary body was removed in a piece or sucked out under direct vision, and the would was closed in layers. In all experimental dogs, pre- and postoperative fasting blood sugar was measured, and the brain and pancreas were removed and fixed in 10 % neutral formalin solution following intracarotid artery infusion of 10% neutral formalin. The removed brain was examined and the pancreas was stained with hematoxylin-eosin, Maldonado, and Toluidine blue sating methods. The following results were obtained: 1. The average preoperative fasting venous blood sugar was 98.5+/-5.4mg% in 20 mongrel dogs. 2. In five hypophysectomized dogs, their preoperative average blood sugar was 99.2+/-5.2mg% and their postoperative blood sugar was decreased in the rage from 13.0 to 35.4mg% during the period from 56 to 77 days. 3. In ten dogs who received daily intramuscular injection of 2mg dexamethasone following hypophyseetomy, their average venous blood sugar was 99.5+/-6.12mg%, and their postoperative blood sugar was decreased in the range from 9.7 to 30.5mg%. 4. In five normal dogs, the number of cells per islet varied from 14 to 96 and the average number was 45, and the average ratio of alpha, beta to delta cells was 14.2 : 79.4 : 6.4; in hypophysectomized group the average number per islet was 53 and their ratio was 19.5 : 75.1: 5.4; in the group which received dexamethasone for a week following hypophysectomy, the average number per islet was 53 and the average ratio was 14.6 : 80.5: 4.9, and in the group which received dexamethasone for two weeks, the average number per islet was 37 and the ratio was 15.2 : 80.2 : 4.5. 5. The acini in the hypophysectomized dogs were rather atrophic and illustrated mild intracytoplasmic vacuolization, and the Langerhans islet demonstrated exhausted pattern with small and degranulated beta cells. However, the Langerhans islets of hypophysectomized dogs with dexamethasone administration showed regranulated beta cells in one dog. 6. In pancreas of hypophysectomized dogs increased number of mast cells along the interstitial tissue, periductal region, and peripancreatic fat tissue were observed. There were also one or two mast cells in the islet mainly along the capsule of islets. 7. In pancreas of hypophysectomized dog with dexamethasone administration a few mast cells were observed along the lobular margin and just beneath the capsule of the islets.