Atomically Thin Mica Flakes and Their Application as Ultrathin Insulating Substrates for Graphene

By mechanical exfoliation, it is possible to deposit atomically thin mica flakes down to single‐monolayer thickness on SiO₂/Si wafers. The optical contrast of these mica flakes on top of a SiO₂/Si substrate depends on their thickness, the illumination wavelength, and the SiO₂ substrate thickness, and can be quantitatively accounted for by a Fresnel‐law‐based model. The preparation of atomically thin insulating crystalline sheets will enable the fabrication of ultrathin, defect‐free insulating substrates, dielectric barriers, or planar electron‐tunneling junctions. Additionally, it is shown that few‐layer graphene flakes can be deposited on top of a previously transferred mica flake. Our transfer method relies on viscoelastic stamps, as used for soft lithography. A Raman spectroscopy study shows that such an all‐dry deposition technique yields cleaner and higher‐quality flakes than conventional wet‐transfer procedures based on lithographic resists.     

Hepatitis G and C viruses respond to interferon-alpha with different virologic kinetics

The aim of this work was to specify the time course of response to interferon (IFN) of hepatitis G virus (HGV) and hepatitis C virus (HCV) in coinfected individuals. A group of 33 patients, undergoing 12 months of IFN therapy for chronic hepatitis C, was screened for the presence of both HGV and HCV RNAs to select seven coinfected patients. Spontaneous recovery from HGV infection was excluded through the detection of antibodies to the envelope-2 protein of HGV and HCV isolates were genotyped. Within three months of treatment, we found that HGV RNA was transiently cleared in 6/7 patients, but the rate of long-term favorable response was very low (1/7). In addition, considering the same individuals separately, it was shown that HGV and HCV responded to IFN with different kinetics in 5/7 patients. Taken together, these results underscore the importance of the virological basis of the resistance to IFN treatment.     

Sub-Tenon's anaesthesia: an efficient and safe technique

AIM: To evaluate sub-Tenon's anaesthesia as an alternative to peribulbar anaesthesia. METHODS: 109 consecutive patients listed for various eye operations (including cataract, trabeculectomy, and vitrectomy) under peribulbar anaesthesia were operated on under sub-Tenon's anaesthesia instead. After topical anaesthesia a buttonhole was fashioned through the conjunctiva and Tenon's capsule 10 mm posterior to the limbus. 1.5 ml of lignocaine 2% was then delivered to the posterior sub-Tenon's space using a blunt cannula. The surgical procedure was performed immediately after the completion of the anaesthetic procedure. Chemosis, conjunctival haemorrhage, degree of akinesia, and pain scoring were analysed. RESULTS: There were no anaesthesia related complications. The administration of the block was painless for 99.1% of the patients. In all, 97.3% reported no pain during surgery. There was no akinesia when assessed just after the completion of the block and akinesia was limited when assessed after surgery. Chemosis and conjunctival haemorrhage were frequent but caused no intraoperative problems. CONCLUSION: Sub-Tenon's anaesthesia is an efficient and safe anaesthetic technique. It is a good alternative to peribulbar anaesthesia.     

Should diastasis recti be corrected?

From theoretical considerations animals with a higher protein-fat ratio in the body should have a higher maintenance energy requirement (MEm). The literature on this problem shows a non-uniform picture with deviating results. From the results of a series of experiments it is possible to compare the heat production (HP) of male and female animals of the Vietnamese Sway-back breed pigs which vary quite widely in their body composition. The protein-fat ratio was 1.2 for the male and 0.2 for the female animals. In the experiments 4 male and 4 female animals in the live weight range of 20-33 kg and 33-42 kg, respectively, were involved. The HP measurements were carried out in climatized respiration chambers on two levels of energy intake at ambient temperatures of 6 degrees C, 12 degrees C, 18 degrees C, 24 degrees C, 30 degrees C, and 35 degrees C. The dependence of HP on the ambient temperature has been described by a cubic regression function. Thermoneutral temperatures are lower in the female animals caused by the better insulation effect of the backfat. The difference in HP which was expected by the large difference in body composition, was not found. The absolute protein mass determined the correlation to HP. Certainly the difference increased after lowering the ambient temperature. The influence of different factors on HP is discussed.     

Underwater repair of fatigue cracks by gas tungsten arc welding process

A fatigue crack repair method for offshore jacket tubular joints is presented. This method is applicable for fatigue cracks detected and sized by regular inspection techniques such as magnetic particle inspection up to a crack depth in the range of 5 mm. The main advantage of the method relies on its easy implementation allowing to be applied immediately after the crack is detected because equipment required is easy to transport and operate; so, it can be on board of a regular inspection campaign ship. A welding procedure specification has to be prepared and qualified prior to implementation of the repair method, considering particular parameters of the jacket fleet and selecting the welding equipment to be used. The proposed method could reinstall the original fatigue life in early stages of growth avoiding the need of more expensive procedures of repair such as joint clamping.     

Involvement of the esophagus in the cramp-fasciculation syndrome

A 35-year-old male patient presented with symptoms of a cramp-fasciculation syndrome, but also reported difficulties swallowing. Esophageal manometry showed spontaneous nonperistaltic contractions, pathologically increased amplitudes and duration of the contractile complexes, and an asynchronous propagation. Electromyographic evidence of fasciculations in the sternocleidomastoid and pectoralis muscles was found. Apparently all types of peripheral motor fibers can be involved in this heterogeneous syndrome, including cranial motor nerves, the vagal nerve, and enteric motor fibers of the gastrointestinal tract.     

Response at three months is a good predictive factor for newly diagnosed chronic myeloid leukemia patients treated by recombinant interferon-alpha

In a single institution, we have used recombinant interferon- (IFN-) to treat 116 newly diagnosed Philadelphia-positive (Ph+) chronic myeloid leukemia (CML) patients and analyzed the predictive factors for response and survival. The patients whose median age was 50.3 years (range, 9 to 70) were administered IFN- (5 million units/m2/d) subcutaneously. The IFN- dose was subsequently adjusted to maintain the white blood cell and platelet counts between 1.5 and 5 x 10(9)/L, 50 and 100 x 10(9)/L, respectively. At diagnosis, the Sokal score was used to classify the patients into three groups: low (n = 57), intermediate (n = 42), and high risk (n = 16). A complete hematological response (CHR) was achieved in 93 cases (80.2%). Of the 116 patients, 113 were available for cytogenetic evaluation. Fifty patients (43%) achieved a major cytogenetic response (MCR) (=65% marrow Ph- cells), 37 of them having a complete cytogenetic response (CCR). The estimated 5-year survival of the 116 patients was 68% +/- 11% (95% confidence interval [CI]) with a median follow-up of 42 months (range, 3 to 114) and 85% +/- 11% (95% CI) with a median follow-up of 30.9 (range, 3 to 111) when patients were censored at the time of transplantation. Event-free survival at 5 years (adding death and transplant as event) was 46% +/- 11% (95% CI). Using proportional hazards regression to study time-dependent variables, we confirmed that the most significant factor associated with survival was the cytogenetic response (MCR or CCR) (P <.0001). This factor was independent compared with the Sokal score and baseline variables used to calculate the Sokal score. Moreover, using either univariate or multivariate analysis, the achievement of CHR within 3 months was strongly correlated with MCR (P <.0001). Minimum cytogenetic response (mCR, ie, at least 5% of Ph- metaphases) at 3 months was also a significant predictive factor for MCR (P <.0001). These results show that IFN- can induce a high rate of hematological and cytogenetic response when administered in doses leading to myelosuppression. Factors such as the achievement of CHR and mCR within 3 months could be useful to identify early those patients who will not respond to IFN- and who need alternative treatments such as stem cell transplantation.     

Use of a multileaf collimator for the production of intensity-modulated beams

The continuous release of nitric oxide (NO) from the constitutive, endothelial isoform of nitric oxide synthase (e-NOS) serves mainly to keep the vasculature in a continuous state of active vasodilation. Although it has been suggested that NO production from e-NOS might also be affected by hemorrhagic shock (HS), this relationship is still controversial. Therefore, the roles of NO in the pathophysiology in hemorrhagic shock were reviewed. According to the previous reports, NO might play an important role in the pathophysioliogy of HS. In the early phase of HS, it may be possible that NO delivered from e-NOS serves a cytoprotective function in preventing shock-induced organ injury. This opinion suggests that endothelial NO production has a significant modulatory effect on vascular tone during hemorrhage, and that inhibition of NO production permits greater vasconstrictor influences leading to organ injury. NO production in the late phases of HS has an adverse effect on survival rate in the HS model. Moreover, the findings from an animal study of prolonged periods of HS suggest that excessive NO formation, including those produced from i-NOS, induces vascular hypoactivity and they have suggested that NOS inhibitors may improve the therapeutic outcome for patients suffering from HS. Therefore, it may be suggested that NO might play a biphasic role, cytoprotective during the early phase and cytotoxic late in HS.