Shock Synthesis of Decagonal Quasicrystals.

The Khatyrka meteorite contains both icosahedral and decagonal quasicrystals. In our previous studies, icosahedral quasicrystals have been synthesized and recovered from shock experiments at the interface between CuAl5 and stainless steel 304 alloys. In this study, we report a new shock recovery experiment aimed at synthesizing decagonal quasicrystals similar to decagonite, natural Al71Ni24Fe5. Aluminum 2024 and permalloy 80 alloys were stacked together and shocked in a stainless steel 304 recovery chamber. Abundant decagonal quasicrystals of average composition Al73Ni19Fe4Cu2Mg0.6Mo0.4Mn0.3 with traces of Si and Cr were found along the recovered interface between the Al and permalloy. The experiment also synthesized AlNiFe alloy with the B2 (CsCl-type) structure and the metastable Al9Ni2 phase. We present chemical (scanning electron microscopy and electron microprobe) and structural (electron backscatter diffraction and transmission electron microscopy) characterization of the recovered phases and discuss the implications of this shock synthesis for the stability of quasicrystals during high-pressure shocks and for the interpretation of the phase assemblage found in Khatyrka.

Low-temperature behaviour of K2Sc[Si2O6]F: determination of the lock-in phase and its relationships with fresnoite- and melilite-type compounds.

K2Sc[Si2O6]F exhibits, at room temperature, a (3 + 2)-dimensional incommensurately modulated structure [a = 8.9878 (1), c = 8.2694 (2) Å, V = 668.01 (2) Å3; superspace group P42/mnm(α,α,0)000s(-α,α,0)0000] with modulation wavevectors q1 = 0.2982 (4)(a* + b*) and q2 = 0.2982 (4)(-a* + b*). Its low-temperature behaviour has been studied by single-crystal X-ray diffraction. Down to 45 K, the irrational component α of the modulation wavevectors is quite constant varying from 0.2982 (4) (RT), through 0.2955 (8) (120 K), 0.297 (1) (90 K), 0.298 (1) (75 K), to 0.299 (1) (45 K). At 25 K it approaches the commensurate value of one-third [i.e. 0.332 (3)]: thus indicating that the incommensurate-commensurate phase transition takes place between 45 K and 25 K. The commensurate lock-in phase of K2Sc[Si2O6]F has been solved and refined with a 3 × 3 × 1 supercell compared with the tetragonal incommensurately modulated structure stable at room temperature. This corresponds to a 3 × 1 × 3 supercell in the pseudo-orthorhombic monoclinic setting of the low-temperature structure, space group P2/m, with lattice parameters a = 26.786 (3), b = 8.245 (2) c = 26.824 (3) Å, ß = 90.00 (1)°. The structure is a mixed tetrahedral-octahedral framework composed of chains of [ScO4F2] octahedra that are interconnected by [Si4O12] rings with K atoms in fourfold to ninefold coordination. Distorted [ScO4F2] octahedra are connected to distorted Si tetrahedra to form octagonal arrangements closely resembling those observed in the incommensurate structure of fresnoite- and melilite-type compounds.

Vacancy pairing and superstructure in the high-pressure silicate K1.5Mg2Si2O7H0.5: a new potential host for potassium in the deep Earth.

The high-pressure silicate K1.5Mg2Si2O7H0.5, synthesized and characterized by Welch et al. [(2012), Am. Mineral. 97, 1849-1857], has been re-examined with the aim of determining the nature of the superstructure noted in their study. The composition corresponds to a 1:1 combination of KMg2Si2O7H and K2Mg2Si2O7 end-members, but it is not a solid solution. Single-crystal X-ray diffraction data for one of the original K1.5Mg2Si2O7H0.5 crystals synthesized at 16 GPa/1573 K, has been collected using a much longer exposure time in order to improve the intensity statistics of weak superlattice reflections identified by Welch et al. (2012). The superstructure has been determined using a superspace approach as having the superspace group Cmcm(0,ß,0)00s and t0 = 1/16 with refined parameters a = 8.7623 (10), b = 5.0703 (7), c = 13.2505 (11) Å, V = 588.69 (12) Å3. This structure corresponds to one with the conventional space group Pbnm and unit-cell parameters a = 8.7623 (10), b = 20.281 (3), c = 13.2505 (11) Å, V = 2354.7 (5) Å3 and is based upon a super-sheet motif in which ordering involves rows of pairs of vacant interlayer K sites. This is the third topologically distinct structure type for the KMg2Si2O7H-K2Mg2Si2O7 join and suggests that there is very limited solid solution, and so it can be expected that each of the three structures (P63cm, P\bar 3 1m and Pbnm) has its own stability field, rather than being part of a continuous compositional series based upon a single structure type. As such, K1.5Mg2Si2O7H0.5 should be considered as a potentially significant host of K in the Earth's mantle.

Open intensive care units: a regional survey about the beliefs and attitudes of healthcare professionals.

AIM: We aimed at assessing the opinion and degree of acceptance of physicians and nurses in Intensive Care Units (ICUs) toward an open ICU as our regional ethical committee has advised that ICU visitation policies be reformed using such a new approach. METHODS: This was a descriptive, cross-sectional, multicenter survey using the Beliefs and Attitudes toward Visitation in ICU Questionnaire mailed to the ICUs in our region. RESULTS: A total of 28 ICUs were invited, and 25 agreed to participate in this survey; 377 nurses and 230 physicians were surveyed with overall response rates of 94.9%% and 84.7%%, respectively. Nurses considered an open visiting policy to be an infringement on patient privacy (P<0.01), a possible interference with interactions between caregivers (P<0.01) and an impediment to their duties (P<0.05). They also significantly differed from physicians in considering open visitations a cause of more adverse hemodynamic events (P<0.05) and higher physiological and psychological stress for patients (P<0.05). With regard to attitudes, nurses strongly disagreed more frequently with the following: allowing everyone to visit the patient, accepting an open visitation policy in their unit, giving control of the visitation policy to the patient (P<0.01) and adapting visitation to the culture/ethnicity of the patients (P<0.0001). CONCLUSIONS: This study points out that, in our region, physicians are more liberal and able than nurses to "customize" their wards to the specific psychosocial and emotional needs of patients and visitors.

Clinical Recovery despite Cortical Cerebral and Cerebellar Damage in Heat Stroke.

The prognosis of heat stroke has considerably improved with a mortality rate drop to 10% when therapeutic measurements including external cooling and aggressive rehydration are adopted. The role of imaging in predicting prognosis is uncertain. Some noted that development of cortical cerebellar atrophy is associated with development of a pancerebellar syndrome, while others suggested that evidence of cerebral cortical damage due to hypoxic-ischemic injury implies a poor prognosis. We observed a 17-year-old female who presented with lost of consciousness and seizure while jogging on a hot summer day followed by multi-organ failure. Brain MRI revealed a symmetric area of T2 hyperintensity and decreased diffusion in the cortical gyri of the frontal lobes. The patient made a complete recovery. MRI two years later showed disappearance of signal changes in the frontal cortex, but progressive atrophy of the cerebellum which was clinically silent. Our observation challenges the view of a close correlation between the imaging findings and prognosis in heat stroke.

Evaluation of an uncalibrated arterial pulse contour cardiac output monitoring system in cirrhotic patients undergoing liver surgery.

BACKGROUND: The pulmonary artery catheter is invasive and may cause serious complications. A safe method of cardiac output (CO) measurement is needed. We have assessed the accuracy and reliability of a recently marketed self-calibrating arterial pulse contour CO monitoring system (FloTrac/Vigileo) in end-stage liver failure patients undergoing liver transplant. The pattern of alterations known as cirrhotic cardiomyopathy, and the transplant procedure itself, provided an evaluation under varying clinical conditions. METHODS: The cardiac index was measured simultaneously by thermodilution (CI(TD): mean of four readings) using a pulmonary artery catheter and pulse contour analysis (CI(V): mean value computed by the FloTrac/Vigileo over the same time period). Readings were made at 10 time-points during liver transplant surgery (T1-T5) and on the intensive care unit (T6-T10). CI(V) was computed using the latest Vigileo software version 01.10. RESULTS: A total of 290 paired readings from 29 patients were collected. Mean (SD) CI(TD) was 5.2 (1.3) and CI(V) was 3.9 (0.9) litre min(-1) m(-2), with a corrected for repeated measures bias between readings of 1.3 (0.2) litre min(-1) m(-2) and 95% limits of agreement of -1.5 (0.2) to 4.1 (0.3) litre min(-1) m(-2). The percentage error (2SD(Bias)/meanCI(TD)) was 54%, which exceeded a 30% limit of acceptance. Low peripheral resistance and increasing bias were related (r=0.69; P<0.001). The Vigileo system failed to reliably trend CI data, with a concordance compared with thermodilution below an acceptable level (at best 68% of sequential readings). CONCLUSIONS: In cirrhotic patients with hyperdynamic circulation, the Vigileo system showed a degree of error and unreliability higher than that considered acceptable for clinical purposes.

False positive tardus-parvus waveforms after liver transplantation: a case of wide discrepancy between donor and recipient hepatic arteries mimicking anastomotic stenosis.

BACKGROUND: Parvus-tardus waveforms of the hepatic artery after liver transplantation usually indicate an arterial complication and severe impairment of hepatic arterial perfusion with a sensitivity of 91% and a specificity of 99.1%. Thus, it has been emphasized that detection of such waveforms should prompt emergency angiography. MATERIALS AND METHODS: Arterial reconstruction during a liver transplantation was successfully accomplished by an end-to-end anastomosis, performing a "flute-spout" widening of the anastomosis with a 7/0 prolene running suture between a small recipient proper hepatic artery and the donor common hepatic artery. RESULTS: On day 7 posttransplantation color Doppler ultrasonography revealed a parvus-tardus waveform pattern in the hepatic arterial flow. Computed tomographic (CT) angiography showed only a caliber discrepancy between the donor and recipient stumps, excluding an arterial stenosis or thrombosis. Since normal liver function persisted, the patient underwent routine follow-up. After 15 months the patient was alive and well; hepatic artery spectral waveforms were unchanged and liver functions were consistent with a mild hepatitis C virus (HCV) recurrence. CONCLUSIONS: This is a report of false positive tardus-parvus waveforms, due to a discrepancy between the donor and recipient arteries despite a wide anastomosis. Knowledge of technical reconstruction details may be helpful for correct interpretation of color Doppler findings. CT angiography should be considered before more invasive examinations.

The "You Are Not Alone" care program for liver transplantation.

Current clinical practice is based on the principles of efficacy, appropriateness, efficiency, quality, and safety. Compliance with these tenets requires experienced medical and nursing staff, and active participation of patients and their families in the planned therapeutic program. To match patients' expectations on quality and safety of care and spur active participation in the transplant care process, we set up an integrated, multiphase, multidisciplinary care program devoted to liver transplantation (LT) candidates, engrafted patients, and their families: the "Non Sei Solo" care program (You Are Not Alone). The basic principle of the care program was that, to provide efficient and effective education to their patients, health care professionals need to learn how to teach and what to teach, acquire successful communication skills, and monitor the process of education. The methodology encompassed 5 distinct phases: phase 1, exploration of patients' needs, by means of a questionnaire devoted to waitlisted and engrafted patients and their care givers; and phase 2, creation of 16 patient-oriented educational brochures directed to patients and their families. Once created, the educational brochures were presented, discussed, and amended during a consensus meeting involving all transplantation nurses and physicians (phase 3). To acquire the necessary skills and ease communication with patients, the transplantation nurses, physicians, surgeons, and anesthesiologists attended a 6-month counseling course under the tutorial of an expert counselor (phase 4). Finally, in June 2007 the program started officially with monthly meetings with patients and their families, guided hospital tours on patient request, and activation of a toll-free phone number to provide support to patients and answer their questions.

Potential applications of extracorporeal photopheresis in liver transplantation.

Extracorporeal photopheresis (ECP) is an immunomodulatory therapy performed through a temporary peripheral venous access with documented efficacy in heart and renal transplantation. We originally reported that ECP represented a valuable alternative to treat graft rejection in selected liver transplant (OLT) recipients. We have investigated potential applications of ECP for prophylaxis of allograft rejection. The first field explored was the use of ECP for delayed introduction of calcineurin inhibitors (CNI) among high-risk OLT recipients seeking to avoid CNI toxicity. In 42 consecutive patients that we assigned to prophylaxis with ECP, we were able to delay CNI introduction after postoperative day 8 in one-third of them. The second field was the use of ECP for prophylaxis of acute cellular rejection among ABO-incompatible OLT recipients. In our experience, none of 11 patients treated with ECP developed a cell-mediated rejection. The third field was ECP application in hepatitis C virus-positive patients seeking to reduce the immunosuppressive burden and improve sustainability and efficacy of preemptive antiviral treatment with interferon and ribavirin. Among 78 consecutive patients, we were able to start preemptive antiviral treatment in 69.2% of them at a median time from OLT of 14 days (range = 7 to 130 days). Thirty-six (66.7%) patients completed the treatment course with an end of treatment virological response of 50.0% and a sustained virological response of 38.9%. These preliminary results await validation in larger prospective studies with longer follow-up periods.

Liver transplantation due to Herpes Simplex virus-related sepsis causing massive hepatic necrosis after thoracoscopic thymectomy.

Following thorascopic thymectomy performed because of myasthenia gravis, a 25-year-old man was affected by fulminant hepatic failure (FHF) of unknown etiology. He was then transferred to our department, where his clinical situation worsened with the onset of renal failure, shock, coagulopathy and coma. Given the young age of the patient, the immediate availability of a donor, and the absence of a definite diagnosis of sepsis at the time, it was decided to proceed with liver transplantation. The results of a polymerase chain reaction (PCR) test (a technique that was unavailable at the referring hospital), which arrived only a few hours later, indicated the presence of herpes simplex virus (HSV) DNA in several of the patient's samples; this led to the formulation of a diagnosis of FHF due to HSV. It is worth noting that HSV-IgM and HSV-IgG assays had always been negative in this patient. Despite acyclovir therapy with initially encouraging clinical results, the patient died several days later because the viral infection had spread to the graft, lungs, heart, spleen, stomach and kidneys. Since evaluating antibody response is not always useful in diagnosing HSV infection, and particularly if PCR methodology is unavailable, it is worth initiating early empiric antiviral therapy when the etiology of FHF is indeterminate This is because the timeliness of treatment while awaiting virological confirmation may be critical to survival. If a liver transplantation becomes mandatory, careful consideration should be given to the extent of the viral infection and its response to therapy because of the possibility of viral spread to the graft.

[Occupational diseases in agricultural workers 2002-2006]. / Malattie professionali in agricoltura 2002-2006.

The authors have examined the data of the occupational diseases in agriculture in the period 2002-2006; such data evidence as in these years there has been an increase of the number of the denunciations of occupational diseases. The increase is referred to new emergent diseases" as occupational the syndrome of the carpal tunnel and the tendinitises. The acknowledgment of new occupational diseases must be accompanied also by an effective promotion of the security of workers.

[Accidents at work in agriculture workers in the period 2002-2006]. / Infortuni in agricoltura nel quinquennio 2002-2006.

The authors consider the accidents happened in agricultural environment in the period from 2002 to 2006. The data of the Inail evidence a decrease of the denounced events, but with a reduction of the occupied workers. Such data make demonstrate that not it there has not been an improvement. For this reason it's necessary put in action informative and formative campaigns about the culture of the prevention of agricultural accidents.

[Accidents at work in handicraft workers in the period 2002-2006]. / Infortuni in artigianato nel quinquennio 2002-2006.

The authors consider the phenomenon of the accidents at work in the handicraft workers in the last period; the data examined demonstrate that in this work environment there has not been an evident decrement of the cases in comparison to the past. It's however always necessary to promote and improve the preventional measures in these particular job places.

[Good practices and techniques for prevention of accidents at work and occupational diseases. New database of Inail]. / La ricerca di buone pratiche e di buone tecniche aziendali utili alla prevenzione degli infortuni e delle malattie professionali la nuova banca dati dell'Inail.

The project "The publication of good practices and good techniques for prevention" is one the priorities of nail. This computerized system for the collection of good practices and standards of Good Technology is aimed to health and safety of workers. The basic objective of the database is to provide a valuable tool, usable, dynamic and implemented, in order to facilitate and direct the access to BP and BT it by people responsible for SSL. At the same time constitutes a tool strategically important for enterprises (especially SMEs) in terms of technological innovation and competitiveness, related to the prevention, safety and health of workers. The realization of this project has involved many of the professionals (chemists, engineers, doctors, biologists, geologists, etc.), and everyone gives his intake of qualified professional competence.

Nurses' knowledge and application of evidence-based guidelines for preventing ventilator-associated pneumonia.

AIM: The aim of the study was to evaluate the nurses' knowledge and to highlight the causes that hinder guidelines implementation. EXPERIMENTAL DESIGN: descriptive study. SETTING AND PARTICIPANTS: 106 nurses working in the ICUs of a major Italian hospital of national importance. INTERVENTION: administration of a questionnaire listing 21 non-pharmacological strategies considered the most useful in the literature. RESULTS: Eighty-four nurses responded to the questionnaire. Only 19 (22.6%) declared that their knowledge of ventilation associated pneumonia (VAP) and the strategies used to prevent it were satisfactory, whereas 46 (54.8%) declared that they were poorly informed; 68 nurses (80.9%) said that they applied one or more strategies, and 15 (17.9%) that they applied none. The reasons given for not applying the strategies were: method not foreseen in Department protocols (31.5%), lack of the necessary resources (14.3%), disagreement with the method (3.2%), high costs (2.6%), the possibility of causing discomfort (1%) or side effects (0.6%). CONCLUSIONS: In our experience, VAP preventive strategies are widely applied by nurses, but not in a responsible and informed manner. It is important to ensure that nurses receive continuous training and are involved in drawing up and updating Departmental protocols and guidelines for care and behaviour.

Perioperative anesthetic management for laparoscopic kidney donation.

OBJECTIVES: To report a single-center experience about the perioperative and anesthetic management of laparoscopic living kidney donation. PATIENTS AND INTERVENTIONS: Subjects undergoing laparoscopic (n = 39) (performed between April 2000 and August 2002) and traditional "open" kidney donation (n = 27) received a standard balanced anesthetic technique. However to counterbalance the reported abdominal insufflation-related kidney dysfunction, laparoscopic donors were administered an extra intravascular volume loading with colloid and crystalloid starting on the night before surgery. RESULTS: Laparoscopic donors underwent longer procedures with lower estimated blood losses (P =.0001), were intraoperatively administered higher amounts of intravenous fluids (P <.01), showed less postoperative analgesic requirement (P <.0001), shorter intensive care unit and overall hospitalization (P <.001), quicker resumption of solid oral intake (P <.01), and full return to work (P <.001) with no difference in the postoperative complication rate. Diuresis resumed intraoperatively in all recipients and early graft function did not differ between the two groups, although the serum creatinine declined earlier, but not significantly, in those receiving kidneys procured by the traditional method. No difference was seen in graft rejection rates. DISCUSSION AND CONCLUSIONS: Laparoscopic kidney donation does not require a particularly complex or expensive anesthetic management or approach; as it has been suggested that intra-abdominal hypertension coming from CO(2) insufflation inside the donor's peritoneal cavity may threaten graft function, during laparoscopic kidney donation it is advisable to adopt a strategy for "renal protection." Thus, when a laparoscopic kidney donation is performed at our center, a multidisciplinary approach is commonly adopted based on three key points: perioperative positive volemic balance in donors; intraoperative urinary output of at least 100 mL/h; inflation with an abdominal pressure not exceeding 12 mm Hg.

Selection and preparation of candidates for combined liver-kidney transplantation: experience at a single center-two case reports.

BACKGROUND: The published experiences of combined liver-kidney transplantation (LKT) are favorable, but there is still no uniformity concerning the impact on hepatorenal syndrome, or in cases of symptomatic hepatorenal polycystic disease. Herein we describe our experience with two LKTs, with particular reference to the selection and preparation of the candidates, and the surgical approach. METHODS: Between 1996 and June 2003, we performed 430 liver transplants in 398 recipients, including two LKTs: one in a patient with hepatorenal polycystic disease (case 1) and the other in a patient with HBV(+) cirrhosis undergoing dialysis after a previous isolated kidney transplant (case 2). RESULTS: In case 1, LKT and right nephrectomy were performed 2 months after a left lumbar nephrectomy. In case 2, LKT was performed 10 months after an isolated kidney transplant, without removing the first graft, which recovered function after 3 months. Both patients are now in good health with functioning grafts. CONCLUSIONS: LKT requires careful selection and preparation of candidates to optimize the probability of success. In well-compensated dialyzed patients with cirrhosis due to viral hepatitis, we believe that a combined approach is indicated after antiviral therapy. In cases of hepatorenal cystic disease, a two-stage surgical approach makes it possible to eliminate the risk of infection and intracyst hemorrhage in nonfunctioning polycystic kidneys.

Hepatic resection after liver transplantation as a graft-saving procedure: indication criteria, timing and outcome.

BACKGROUND: Hepatic resection is uncommon after liver transplantation (LT), but can be a graft-saving procedure in selected cases. Herein we describe the criteria, outcome, and timing of this procedure in our series. METHODS: Between January 1996 and December 2002, 397 LTs were performed in 367 recipients, of whom 12 patients (3.2%) subsequently underwent liver graft resections because of ischemic-type biliary lesions (ITBLs) (n = 5, 41.6%), segmental hepatic artery thrombosis (S-HAT)(n = 3, 25%), recurrent hepatocellular carcinoma (HCC) (n = 2, 16.6%), liver abscess (n = 1, 8.3%), or liver trauma (n = 1, 8.3%). The patients were divided into group 1 (n = 3 all with S-HAT) who underwent early resections (within 3 months of LT), and group 2 (n = 9) who underwent late resections (after 3 months). The outcomes and postoperative mortality ratio (within 30 days) were compared. RESULTS: The resections consisted of four left lobectomies, three right hepatectomies, two extended right hepatectomies, one segmentectomy, one anterior trisegmentectomy, and one right lateral sectoriectomy. The perioperative mortality rate was 66.6% in group 1 (one case of myocardial infarction and one of sepsis), and 22% in group 2 (one case of sepsis and one of hepatic failure). CONCLUSIONS: Late resections in stable patients with damage confined to the graft yield good prognosis. Even major resections are feasible graft-saving procedures. In contrast, early hepatic resections in S-HAT are associated with a worse outcome. Retransplantation should be considered the first-choice option. Sepsis significantly affects the postsurgical course.