Magnetic Friedel Oscillation at the Fe(001) Surface: Direct Observation by Atomic-Layer-Resolved Synchrotron Radiation

The surface magnetism of Fe(001) was studied in an atomic layer-by-layer fashion by using the in situ iron-57 probe layer method with a synchrotron Mössbauer source. The observed internal hyperfine field H_{int} exhibits a marked decrease at the surface and an oscillatory behavior with increasing depth in the individual upper four layers below the surface. The calculated layer-depth dependencies of the effective hyperfine field |H_{eff}|, isomer shift δ, and quadrupole shift 2ϵ agree well with the observed experimental parameters. These results provide the first experimental evidence for the magnetic Friedel oscillations, which penetrate several layers from the Fe(001) surface.

Formation of NaCl-type monodeuteride LaD by the disproportionation reaction of LaD2.

Previous x-ray diffraction measurements revealed the pressure-induced decomposition of an fcc LaH2.3 into H-rich and H-poor fcc phases around 11 GPa. The present neutron diffraction measurements on LaD2 confirm the formation of NaCl-type LaD as a counterpart of the D-rich LaD2+δ by disproportionation. First-principles enthalpy and lattice dynamic calculations demonstrate that the NaCl-type LaH is stabilized at high pressures and can be recovered at ambient conditions. Finding the NaCl-type LaH will pave the way for investigations on the site-dependent nature of hydrogen-metal interactions.

Maximizing T c by tuning nematicity and magnetism in FeSe1-x S x superconductors.

A fundamental issue concerning iron-based superconductivity is the roles of electronic nematicity and magnetism in realising high transition temperature (T c). To address this issue, FeSe is a key material, as it exhibits a unique pressure phase diagram involving non-magnetic nematic and pressure-induced antiferromagnetic ordered phases. However, as these two phases in FeSe have considerable overlap, how each order affects superconductivity remains perplexing. Here we construct the three-dimensional electronic phase diagram, temperature (T) against pressure (P) and isovalent S-substitution (x), for FeSe1-x S x . By simultaneously tuning chemical and physical pressures, against which the chalcogen height shows a contrasting variation, we achieve a complete separation of nematic and antiferromagnetic phases. In between, an extended non-magnetic tetragonal phase emerges, where T c shows a striking enhancement. The completed phase diagram uncovers that high-T c superconductivity lies near both ends of the dome-shaped antiferromagnetic phase, whereas T c remains low near the nematic critical point.

Stability of microcystins from cyanobacteria--II. Effect of UV light on decomposition and isomerization.

Microcystins are very potent hepatotoxins and strong liver tumor promoters produced by cyanobacteria, and their occurrence has been reported all over the world. They could threaten human health when toxic Microcystis occurs in water supply reservoirs. In this study, we examined the stability of microcystins during photolysis with UV light. The toxins were easily decomposed by UV light at wavelengths around the absorption maxima of the toxins and the decomposition depended on the intensity of the light. The half-life of microcystin LR by 147 microW/cm2 UV irradiation was 10 min, and the toxin was completely decomposed by 2550 microW/cm2 UV after 10 min. When the toxins were irradiated with weaker UV light, isomerization was also observed by a different mechanism from that during photolysis by sunlight and pigment, and several products including three geometrical isomers of the conjugated diene of Adda were detected. Microcystin RR showed almost the same behavior as that of microcystin LR under the same conditions. Since no noxious products were formed in the present study, a water treatment including UV irradiation is very possible for removing microcystins from raw water.

Stability of microcystins from cyanobacteria--IV. Effect of chlorination on decomposition.

Microcystins, the cyclic heptapeptide toxins produced by cyanobacteria such as Microcystis, show tumor-promoting activity through inhibition of protein phosphatases 1 and 2A. They potentially threaten human health, and are increasing the world-wide interest in the health risk associated with cyanobacterial toxins. In this study, the effect of chlorination on the decomposition of microcystins-LR and -RR was examined. The toxins were easily decomposed by chlorination with sodium hypochlorite, and the decomposition depended on the free chlorine dose. In this operation, many reaction products were formed, one of which was determined to be dihydroxymicrocystin formed through the chloronium ion at the conjugated diene of Adda [3-amino-9-methoxy-10-phenyl-2,6,8-trimethyl-deca-4(E), 6(E)-dienoic acid], followed by hydrolysis. Other products may be its stereoisomers and/or regioismers. No noxious products were detected from the chlorination process of microcystin-LR. Although these results suggested that chlorination at an adequate chlorine dose is very effective for the removal of microcystin in raw water, preoxidation of the cell itself with chlorine must be avoided, because it frequently causes toxin release from algae and produce trihalomethanes during water treatment.

Operative and postoperative choledochofiberoscopy.

Choledochofiberoscopy is effective for both diagnosis and therapy. It is a valuable diagnostic technic because it permits a definite diagnosis and it allows the surgeon to determine the operative method by direct viewing and by biopsy of the biliary tract wall. Choledochofiberoscopy is therapeutically valuable because it permits cleaning of the bile duct, the removal of retained or remnant stones in the common and intrahepatic ducts, and the removal of granuloma and benign tumor with forceps under direct vision.

Clinical applications of Ga-67 DFO-DAS-fibrinogen.

As a result of our preliminary study which confirmed the safety and promising clinical usefulness of 67Ga-DFO-DAS-fibrinogen, scintigrams were taken on seven patients with suspected thrombosis. No evidence of radioactivity accumulation was found in the sites of suspected thrombi. However, in one patient accumulation of 67Ga-fibrinogen was observed in thrombi localized in the obstructed internal shunt for hemodialysis. A photon-deficient area corresponding to a gigantic thrombus in the left atrium was seen in an early 67Ga-fibrinogen image in a patient with mitral stenosis. Accumulation of radioactivity in the atrial thrombus was not observed in a later image. The necessity of performing 67Ga-fibrinogen scintigraphy in the acute phase of thrombus formation is discussed. The promising usefulness of 67Ga-fibrinogen for the early detection of thrombus formation in internal shunts for hemodialysis is also emphasized.

Medical electronics in surgery.

I have described the results of a telemetering radio capsule which we used in the clinical assessment of digestive disease. This method has many merits which we have never found with other methods. This is one example of the clinical use of medical electronics. Medical electronics provides surgeons with many useful aids to improve diagnosis and treatment of their patients. Medical electronic technics should be used more often.

The patient-physician interactions as seen by undergraduate medical students.

CONTEXT: The interaction between a physician and his or her patient is complex and occurs by means of technical performance and through a personal relationship. OBJECTIVE: To assess the interaction between the medical professional and his or her patient with the participation of medical students assuming a role as observers and participants in a medical appointment in an outpatient office. DESIGN: Questionnaire interview study. SETTING: General Medicine outpatient offices, Hospital das Clínicas, Faculty of Medicine, University of São Paulo. PARTICIPANTS: Medical students performed an ethnographical technique of observation, following 199 outpatient medical appointments with Clinical Medicine Residents. MAIN MEASUREMENTS: A questionnaire filled out by observer students measured the physician's attitudes towards patients, as well as patients' expectations regarding the appointment and his or her understanding after its completion. RESULTS: Patients showed higher enthusiasm after the appointment (4.47 +/- 0.06 versus 2.62 +/- 0.10) (mean +/- SEM), as well as some negative remarks such as in relation to the waiting time. The time spent in the consultation was 24.66 +/- 4.45 minutes (mean +/- SEM) and the waiting time was 123.09 +/- 4.91 minutes. The physician's written orientation was fairly well recalled by the patient when the doctor's letter could be previously understood. CONCLUSION: Patients benefit from physicians who keep the focus on them. In addition, this program stimulated the students for their accomplishment of the medical course.

[Toxicological studies on dibekacin for intravenous injection use. II. Chronic toxicity in rats (author's transl)].

The toxic effects of dibekacin sulfate (DKB) in male and female rats were examined in chronic toxicity test (intraperitoneal injection), and the following results were obtained. 1) No death was noted in both male and female. 2) In general conditions, the excretion of soft or diarrheal stool was noted in groups of more than 20 mg/kg of either sex. The mean body weight was less than the control during a certain period in the male group of 40 mg/kg and in the female group of 20 mg/kg. But, in the food intakes, no particular change was noted in each group of either sex. 3) In the auricle reflex, no abnormality was noted in each group of either sex. 4) In the hematological test, the findings such as an increase of BUN, anemia, etc. were noted in the groups more than 10 mg/kg of male and more than 20 mg/kg of female. 5) In the histopathological study, evident degenerative changes of renal tubular epithelia were noted in the groups which were administered more than 20 mg/kg of DKB in both male and female, but no evident pathological findings due to the renal failure were noted in the groups of less than 10 mg/kg. Several slight changes of the thyroid gland noted in a few rats of DKB administration group of both male and female seemed to be artifact, and inflammatory changes owing to intraperitoneal injection were occasionally noted in the peritoneum of DKB injected animals. 6) Considering the above results, "the maximal non effective dose" was estimated to be 10 mg/kg in both male and female.

[Toxicological studies on dibekacin for intravenous injection use. I. Subacute toxicity in rats and rabbits (author's transl)].

Dibekacin sulfate (DKB) dissolved in physiological saline J.P. was administered to rats intraperitoneally and rabbits intravenously for subacute 35-day toxicity test. The results were as follows: I. Wistar-strain rats (1) All the animals of both male and female died in the group with 500 mg/kg. (2) In general conditions stretching physical positions, decrease in spontaneous movements, decrease in respiration rates, unsteady steps of walking and muscular relaxation developed in the groups of high doses of either sex. The effects through the administration of this drug were also noted on the progress of body weights and food intakes in the groups of high doses. (3) In the hematological and histopathological studies, degenerative and reparative changes of tubular epithelia were evidently noted in the groups which were administered more than 100 mg/kg of DKB in both male and female. No pathological findings were noted in administration groups less than 20 mg/kg. (4) Microscopically, slight inflammatory changes were noted in the bladder of the male groups of high doses and the direct stimulative effects on the peritoneum due to intraperitoneal administration were noted but slightly in the serous membrane of the liver, spleen and the gastrointestinal tracts. (5) Judging from the above-mentioned results, "the maximal non toxic dose" through the intraperitoneal administration to rats of this drug was assumed 20 mg/kg in either sex. II. Albino rabbits (1) Neither remarkable change in the general conditions nor death was noted in each administration group. (2) The increase in the mean body weight in each group was almost similar to the control value. They consumed the amounts of food given. (3) The specific abnormal finding was not noted in the hematology and biochemical tests of serum or urine. (4) Since no change was noted on ERG in each rabbits, we estimate there is no effect to the visual organs. (5) In histopathological study, several changes revealed in some organs through the macroscopic findings, organ weights and microscopic findings but they were no more the serious changes attributable to administration. (6) We estimate "the maximal non effective dose" in this test was 10 mg/kg.

[Non-Hodgkin's lymphoma of the nasal cavity and paranasal sinuses: clinicopathologic study of ten cases].

Ten patients with non-Hodgkin's lymphoma originated in the nasal cavity (four patients) and in the paranasal sinuses (six patients) were treated mainly with irradiation and combination chemotherapy including adriamycin. According to the TNM AJC staging system, four patients were in stage T1-T2, and six patients were in stage T3-T4. Nine patients, other than one with stage IV (Ann Arbor) disease, achieved complete remission. Death due to lymphoma occurred in four patients, 4 to 39 months following diagnosis. Three of these patients developed systemic extranodal dissemination, and died in a short time after relapse. Death due to second malignancies occurred in two patients. One died of acute myelogenous leukemia, and the other died of colon cancer, 26 and 53 months after diagnosis, respectively. Four patients were alive and disease-free, from 23 to 68 months following diagnosis (median 40 months). Out of four patients who died of disease, three were in stage T3-T4, and one was in stage T1. Two patients with stage T1 originated in the nasal cavity were both alive and disease-free. Except for lymphomas with stage T1 originated in the nasal cavity, more intensive chemotherapy should be instituted in an attempt to achieve better disease-free survival.

[Hemophagocytic syndrome in a patient with immunoblastic lymphadenopathy-like T-cell lymphoma].

We report a 70-year-old male case of immunoblastic lymphadenopathy-like T-cell lymphoma (IBL-T) complicated by hemophagocytic syndrome (HPS) as a terminal event. The patient experienced fever and systemic lymphadenopathy after 22 months' remission of IBL-T. He developed acute hepatic failure and consumption coagulopathy rapidly, and died on the 7th hospital day. Serum levels of cytokines, including interferon-gamma and tumor necrosis factor-alpha, were elevated. Postmortem bone marrow aspirate showed a marked proliferation of benign-looking macrophages, some of which phagocytized erythrocytes and platelets. Because there were no preceding viral or bacterial infections, the HPS of this case was assumed to be associated with IBL-T at relapse.

[Electrolyte abnormality and renal insufficiency in malignant lymphoma; clinical and pathological analysis in 123 cases].

The clinical studies about the electrolyte abnormality (EA) in patients with malignant lymphoma (ML) are rarely reported. We analyzed the EA and renal insufficiency in 123 patients with ML between June. 1976 and Jan. 1989; 8 patients with Hodgkin's disease, and 115 patients with non-Hodgkin's lymphoma (NHL). Before treatment, the incidence of the EA was 24.2% and hypercalcemia, hypocalcemia, and hyperkalemia were predominant. After treatment it became to 74.7% and the number of hyponatremia and hypokalemia increased. The incidence of proteinuria and renal insufficiency (serum creatinine above 1.5 mg/dl), were 7.3% and 2.4% before treatment, and became to 26.8% and 26.8% after treatment, respectively. There was a significant difference between two groups with and without the EA before treatment as for serum lactate dehydrogenase (LDH) levels (p less than 0.01), clinical stages (p less than 0.05) and the incidence of bone marrow involvement (p less than 0.01). In 34 autopsied cases, 3 cases showed massive renal involvement and about a half of cases showed various renal changes. The EA before treatment was caused by extrarenal factors, because the incidence of proteinuria and renal insufficiency were almost same to healthy controls. And renal factors play an important role on the E.A after treatment. Above results suggest that the EA before treatment indicates the progress of malignant lymphoma and the EA after treatment means not only the progress of the disease but also therapy-related renal damages.

[A retrospective comparison study of patients old and young with non-Hodgkin's lymphoma].

One hundred patients with diffuse non-Hodgkin's lymphoma were treated with combination chemotherapy including adriamycin. Seventy-one patients were under age 70 and 29 were 70 years or older. The clinical characteristics of the two groups were similar, except that the patients showed elevated serum BUN were in the elderly group. The complete remission rate in the elderly patients (66%) was slightly lower than that in the younger patients (75%) (p = NS). The average length of survival in the elderly patients was significantly shorter than in the younger patients (p less than 0.05) (projected 5-year survival: 28 +/- 11% vs 52 +/- 7%). The duration of remission for all patients in the elderly patients did not differ from that in the younger patients (projected 2-year survival: 40 +/- 10% vs 45 +/- 6%). Death during the induction chemotherapy from causes other than lymphoma occurred in 14% of patients over 70-year-old and in one percent of younger patients. At relapse, the response rate was significantly lower in the elderly patients than in the younger patients (CR+PR: 28% vs 78%, p = 0.03). To prevent toxic death in remission induction therapy, drug dose elderly patients should be attenuated according to their general conditions and performance status.

[Clinical significance of immunophenotype in diffuse non-Hodgkin's lymphoma: with special emphasis on the clinical characteristics of T-cell lymphoma].

The clinical significance of immunophenotyping of the non-Hodgkin's lymphomas (NHL) is still controversial. Therefore, we evaluated the prognostic significance of T- and B-cell phenotype in 102 patients having diffuse non-Hodgkin's lymphoma who had been treated in a majority with Adriamycin-containing regimens. The significant differences in pretreatment clinical variables between the two patient groups were the higher frequency of markedly elevated LDH (greater than or equal to X 2 normal) and the lower frequency of decreased cholesterol level in B-NHL (p less than 0.05). Patients with B-NHL had a higher complete remission (CR) rate (77% vs 59%: p = NS), a significantly better overall survival (62% vs 34% at 3-years: p less than 0.05) and longer duration of remission for all patients (50% vs 27% at 3-years: p less than 0.05). Among forty-five patients with stages III and IV disease of nodal origin (excluding those with diffuse small cleaved histology), the B-cell group was associated with a better prognosis; a higher CR rate (68% vs 41%: p = NS) and a longer duration of remission for all patients (44% vs 12% at 2-years: p less than 0.05). Furthermore, for patients with T-cell phenotype, the primary site was the only prognostic factor; the patients whose disease originated from Waldeyer's ring, nasal cavity, and paranasal sinuses, achieved a better CR rate (92% vs 40%: p less than 0.05) and a longer duration of remission for all patients (48% vs 15% at 2-years: p less than 0.05). We conclude that advanced T-cell lymphoma of nodal origin is a subgroup of patients with very poor prognosis if treated with less intensive chemotherapeutic regimens.