Design and construction of a 9 MeV γ-ray source based on capture of moderated plutonium-beryllium neutrons in nickel.

We have designed and constructed a high-energy γ-ray source for detector characterisation and calibration. The source is a composite type based on a plutonium-beryllium neutron emitter embedded in a paraffin moderator, which is homogeneously mixed with nickel powder. The 9 MeV γ-ray source produces approximately 450 photons per second in 4π when 2.2×105 neutrons per second are emitted, corresponding to a surface flux of 9 MeV γ-rays of approximately 2.5×10-6 cm-2 per emitted neutron. Here we discuss the properties and design of this source, including the characterisation of homogeneity and high-energy γ-ray emission spectra.

From (pi,0) magnetic order to superconductivity with (pi,pi) magnetic resonance in Fe(1.02)Te(1-x)Se(x).

The iron chalcogenide Fe(1+y)(Te(1-x)Se(x)) is structurally the simplest of the Fe-based superconductors. Although the Fermi surface is similar to iron pnictides, the parent compound Fe(1+y)Te exhibits antiferromagnetic order with an in-plane magnetic wave vector (pi,0) (ref. 6). This contrasts the pnictide parent compounds where the magnetic order has an in-plane magnetic wave vector (pi,pi) that connects hole and electron parts of the Fermi surface. Despite these differences, both the pnictide and chalcogenide Fe superconductors exhibit a superconducting spin resonance around (pi,pi) (refs 9, 10, 11). A central question in this burgeoning field is therefore how (pi,pi) superconductivity can emerge from a (pi,0) magnetic instability. Here, we report that the magnetic soft mode evolving from the (pi,0)-type magnetic long-range order is associated with weak charge carrier localization. Bulk superconductivity occurs as magnetic correlations at (pi,0) are suppressed and the mode at (pi, pi) becomes dominant for x>0.29. Our results suggest a common magnetic origin for superconductivity in iron chalcogenide and pnictide superconductors.

[Medical evacuation--part of prehospital management of trauma patients]. / Evacuarea medicala--parte integranta a managementului prespitalicesc a pacientului traumatizat.

Medical evacuation, is a complex action, very much protocolised, with multiple aspects related to a serial data about trauma mechanisms, clinical situation, temporal standards, specific competences. The medical team have to decide which is the fastest, less traumatic, most correct and appropriate possibility for each specific patient, and to manage all the facilities to realise these aims. Medical evacuation as a part of integrative management for the trauma patient could affect significantly either the survival chance and the rehabilitation and depends on rules that have to be in relationship with the patient condition and mechanisms of trauma, distances, medical abilities and competences of the different trauma centers as an evacuation destinations--the performant communication and interconnection between these all links being indispensable.

[Antimicrobial activity of new 4,4'-bipyridine derivatives: and in vitro study]. / Activité antimicrobienne in vitro de nouveaux sels diquaternaires dérivés de la 4,4'-bipyridine.

The antimicrobial and antifungal activity of some 4,4'-bipyridine derivatives were studied. The diffusimetric gelose surface diffusion method with stainless steel cylinders was used to study bacteria and Sabouraud fields for Candida albicans. Comparative analysis of the results led to the following conclusions. Diquaternary salts of 4,4'-bipyridinium possess a remarkable antimicrobial and antifungal activity. The influence of R1 and R2 substitutes in the para or meta position of the benzoylic radical affects selectivity but does not greatly influence activity.

[Retroperitoneal Castleman's disease]. / Boala castleman retroperitoneala.

We present 2 cases of retroperitoneal localisation of Castleman's disease--hyalino-vascular histologic type. A 65 years old woman and a 67 years old man were admitted with the diagnosis of retroperitoneal tumour. The clinical findings were not specific. Surgical removal of the tumour is the treatment of choice. Focal recurrences didn't occur.

[Transhiatal esophagectomy]. / Esofagectomiile transhiatale.

Between 1991-2001, 40 patients underwent esophagectomy without thoracotomy for: caustic esophageal stenosis (26 cases), cervical esophageal cancer (1), lower esophageal cancer (7), and acute post-caustic oesophagitis (2). Thirty-four patients underwent transhiatal esophagectomy, 3 patients had an esophagectomy by "stripping" and in 3 other patients a combination of stripping and transhiatal esophagectomy. Postoperative complications included: injuries of the laryngeal recurrent nerve (2), pulmonary complications (13), anastomotic leakage (5). Two patients died in the postoperative period one from a myocardial infarction and the other from an acute myocardial dilatation. Trans-hiatal esophagectomy can be considered as a viable alternative to transthoracic esophagectomy in the management of the benign and malignant diseases of the esophagus. Transhiatal esophagectomy is a safe method of resection because of its reported lower morbidity and mortality and similar survival rates compared to transthoracic esophagectomy.

[Exceptional etiologies in upper digestive tract bleeding ]. / Exceptii etiologice în HDS.

7 cases, considered as being true etiological exceptions selected from 756 upper gastrointestinal bleeding, are presented. The causes of bleeding were: pancreatic pseudocyst with intracystic hemorrhage broken into duodenum (2 cases), the nonepithelial gastroduodenal tumor (3 cases), the aneurysm of gastroduodenal artery broken into duodenum (1 case) and the aortoduodenal fistula in one patient with a bilateral aorto-iliac by-pass (1 case). The etiological diagnosis could not be established in any cases before the operations. All the cases were operated on, the operation being imposed by the severity of bleeding and having the haemostasis as a main purpose.

Two different primary ophthalmic cancers in a 39-year-old female patient.

The clinical and histopathological findings are described in a 39-year-old female patient with two different primary ophthalmic cancers, involving the adnexa and ocular globe of the same eye. The first primary tumor was a malignant fibrous histiocytoma of the left lower eyelid aggressively invading the nasogenian region, bulbar conjunctiva, episclera, and the cornea over a 36-year follow-up period. The second primary cancer was an unsuspected choroidal malignant melanoma unexpectedly found at histology. The possible correlations between these two malignancies are discussed.