Structural origin of apparent Fermi surface pockets in angle-resolved photoemission of Bi₂Sr(2-x)La(x)CuO(6+δ)

We observe apparent hole pockets in the Fermi surfaces of single-layer Bi-based cuprate superconductors from angle-resolved photoemission. From detailed low-energy electron diffraction measurements and an analysis of the angle-resolved photoemission polarization dependence, we show that these pockets are not intrinsic but arise from multiple overlapping superstructure replicas of the main and shadow bands. We further demonstrate that the hole pockets reported recently from angle-resolved photoemission [Meng et al., Nature (London) 462, 335 (2009)] have a similar structural origin and are inconsistent with an intrinsic hole pocket associated with the electronic structure of a doped CuO₂ plane.

Creation and control of a two-dimensional electron liquid at the bare SrTiO3 surface

Many-body interactions in transition-metal oxides give rise to a wide range of functional properties, such as high-temperature superconductivity, colossal magnetoresistance or multiferroicity . The seminal recent discovery of a two-dimensional electron gas (2DEG) at the interface of the insulating oxides LaAlO(3) and SrTiO(3) (ref. 4) represents an important milestone towards exploiting such properties in all-oxide devices. This conducting interface shows a number of appealing properties, including a high electron mobility, superconductivity and large magnetoresistance, and can be patterned on the few-nanometre length scale. However, the microscopic origin of the interface 2DEG is poorly understood. Here, we show that a similar 2DEG, with an electron density as large as 8×10(13)  cm(-2), can be formed at the bare SrTiO(3) surface. Furthermore, we find that the 2DEG density can be controlled through exposure of the surface to intense ultraviolet light. Subsequent angle-resolved photoemission spectroscopy measurements reveal an unusual coexistence of a light quasiparticle mass and signatures of strong many-body interactions.

Strong electron correlations in the normal state of the iron-based FeSe0.42Te0.58 superconductor observed by angle-resolved photoemission spectroscopy

We investigate the normal state of the "11" iron-based superconductor FeSe0.42Te0.58 by angle-resolved photoemission. Our data reveal a highly renormalized quasiparticle dispersion characteristic of a strongly correlated metal. We find sheet dependent effective carrier masses between approximately 3 and 16m{e} corresponding to a mass enhancement over band structure values of m{*}/m{band} approximately 6-20. This is nearly an order of magnitude higher than the renormalization reported previously for iron-arsenide superconductors of the "1111" and "122" families but fully consistent with the bulk specific heat.

[TVT and TOT: a comparison between these two techniques based on our clinical experience]

A retrospective evaluation and a comparison of results from two minimally invasive surgery techniques that we adopted for the treatment of SUI. MATERIALS AND METHODS. In this study we evaluated 113 selected patients who underwent SUI minimally invasive surgery from 1-1-2000 to 31-12-2007. 87 patients underwent epidural anesthesia. 26 local anesthesia. In Group A (TVT) 61 patients were enrolled, mean age 57.6 (±22). 43 patients (70%) were on menopause. In Group B (TOT out-in) 52 patients were enrolled (for 34 of them we used the Obtape® sling while for 18 the Obtryx® one), their mean age was 58.5 (±20.5) and 39 patients (75%) were on menopause. Patients from both groups did not undergo any past previous urogynecological surgery and suffered from stress urinary incontinence with cervico-urethral hypermobility butno other associated pathology. The pre-operative work-up included an evaluation of patients based on ICS guidelines. RESULTS. Group A (TVT) - mean follow-up 66.3 months, dry patients 53/61 (86.8%). Bladder perforations resolved by catheterization 3/61 (5%). Transient voiding dysfunction 14/61 (22.8%). "De novo" urgency 8/61 (13%). One patient on self-catheterization due to persistent urinary retention underwent a single-side section of the sling with spontaneous micturition and complete continence recovery. Group B (TOT out-in) - mean follow-up 35.5 months, dry patients 43/52 (82%). 4 patients (7.6%) complained oftransient voiding dysfunction, 5 patients (9.5%) for "de novo" urgency, 1 patient underwent a sling removal due to vaginal erosion 4 months after surgery (Obtape®).

TVT and TOT: a comparison between these two techniques based on our clinical experience

Aim of the Study

A retrospective evaluation and a comparison of results from two minimally invasive surgery techniques that we adopted for the treatment of SUI.

Materials and Methods.

In this study we evaluated 113 selected patients who underwent SUI minimally invasive surgery from 1–1-2000 to 31–12–2007. 87 patients underwent epidural anesthesia. 26 local anesthesia. In Group A (TVT) 61 patients were enrolled, mean age 57.6 (±22). 43 patients (70%) were on menopause. In Group B (TOT out-in) 52 patients were enrolled (for 34 of them we used the Obtape® sling while for 18 the Obtryx® one), their mean age was 58.5 (±20.5) and 39 patients (75%) were on menopause. Patients from both groups did not undergo any past previous urogynecological surgery and suffered from stress urinary incontinence with cervico-urethral hypermobility butno other associated pathology. The pre-operative work-up included an evaluation of patients based on ICS guidelines.

Results.

Group A (TVT) - mean follow-up 66.3 months, dry patients 53/61 (86.8%). Bladder perforations resolved by catheterization 3/61 (5%). Transient voiding dysfunction 14/61 (22.8%). “De novo” urgency 8/61 (13%). One patient on self-catheterization due to persistent urinary retention underwent a single-side section of the sling with spontaneous micturition and complete continence recovery. Group B (TOT out-in) - mean follow-up 35.5 months, dry patients 43/52 (82%). 4 patients (7.6%) complained oftransient voiding dysfunction, 5 patients (9.5%) for “de novo” urgency, 1 patient underwent a sling removal due to vaginal erosion 4 months after surgery (Obtape®).

Fermi surface and van Hove singularities in the itinerant Metamagnet Sr3Ru2O7

The low-energy electronic structure of the itinerant metamagnet Sr3Ru2O7 is investigated by angle-resolved photoemission and density-functional calculations. We find well-defined quasiparticle bands with resolution-limited linewidths and Fermi velocities up to an order of magnitude lower than in single layer Sr2RuO4. The complete topography, the cyclotron masses, and the orbital character of the Fermi surface are determined, in agreement with bulk sensitive de Haas-van Alphen measurements. An analysis of the dxy band dispersion reveals a complex density of states with van Hove singularities near the Fermi level, a situation which is favorable for magnetic instabilities.

Bulk superconductivity at 38 K in a molecular system

C(60)-based solids are archetypal molecular superconductors with transition temperatures (Tc) as high as 33 K (refs 2-4). Tc of face-centred-cubic (f.c.c.) A(3)C(60) (A=alkali metal) increases monotonically with inter C(60) separation, which is controlled by the A(+) cation size. As Cs(+) is the largest such ion, Cs(3)C(60) is a key material in this family. Previous studies revealing trace superconductivity in Cs(x)C(60) materials have not identified the structure or composition of the superconducting phase owing to extremely small shielding fractions and low crystallinity. Here, we show that superconducting Cs(3)C(60) can be reproducibly isolated by solvent-controlled synthesis and has the highest Tc of any molecular material at 38 K. In contrast to other A(3)C(60) materials, two distinct cubic Cs(3)C(60) structures are accessible. Although f.c.c. Cs(3)C(60) can be synthesized, the superconducting phase has the A15 structure based uniquely among fullerides on body-centred-cubic packing. Application of hydrostatic pressure controllably tunes A15 Cs(3)C(60) from insulating at ambient pressure to superconducting without crystal structure change and reveals a broad maximum in Tc at approximately 7 kbar. We attribute the observed Tc maximum as a function of inter C(60)separation--unprecedented in fullerides but reminiscent of the atom-based cuprate superconductors--to the role of strong electronic correlations near the metal-insulator transition onset.

Inducible virus-mediated expression of a foreign protein in suspension-cultured plant cells

Although suspension-cultured plant cells have many potential merits as sources of useful proteins, the lack of an efficient expression system has prevented using this approach. In this study, we established an inducible tomato mosaic virus (ToMV) infection system in tobacco BY-2 suspension-cultured cells to inducibly and efficiently produce a foreign protein. In this system, a modified ToMV encoding a foreign protein as replacement of the coat protein is expressed from stably transformed cDNA under the control of an estrogen-inducible promoter in transgenic BY-2 cells. Estrogen added to the culture activates an estrogen-inducible transactivator expressed constitutively from the transgene and induces transcription and replication of viral RNA. In our experiments, accumulation of viral RNA and expression of green fluorescent protein (GFP) encoded in the virus were observed within 24 h after induction. The amount of GFP reached approximately 10% of total soluble protein 4 d after induction. In contrast, neither viral RNA nor GFP were detected in uninduced cells. The inducible virus infection system established here should be utilized not only for the expression of foreign proteins, but also for investigations into the viral replication process in cultured plant cells.

Boron Nitride Nanomesh

A highly regular mesh of hexagonal boron nitride with a 3-nanometer periodicity and a 2-nanometer hole size was formed by self-assembly on a Rh(111) single crystalline surface. Two layers of mesh cover the surface uniformly after high-temperature exposure of the clean rhodium surface to borazine (HBNH)3. The two layers are offset in such a way as to expose a minimum metal surface area. Hole formation is likely driven by the lattice mismatch of the film and the rhodium substrate. This regular nanostructure is thermally very stable and can serve as a template to organize molecules, as is exemplified by the decoration of the mesh by C60 molecules.

Cell-to-cell movement of Potato virus X: the role of p12 and p8 encoded by the second and third open reading frames of the triple gene block

Potato virus X (PVX) requires three proteins, p25, p12, and p8, encoded by the triple gene block plus the coat protein (CP) for cell-to-cell movement. When each of these proteins was co-expressed with a cytosolic green fluorescent protein (GFP) in the epidermal cells of Nicotiana benthamiana by the microprojectile bombardment-mediated gene delivery method, only p12 enhanced diffusion of co-expressed GFP, indicating an ability to alter plasmodesmal permeability. p25, p12, and CP, expressed transiently in the initially infected cells, transcomplemented the corresponding movement-defective mutants to spread through two or more cell boundaries. Thus, these proteins probably move from cell to cell with the genomic RNA. In contrast, p8 only functioned intracellularly and was not absolutely required for cell-to-cell movement. Since overexpression of p12 overcame the p8 deficiency, p8 appears to facilitate the functioning of p12, presumably by mediating its intracellular trafficking. Considering the likelihood that p12 and p8 are membrane proteins, it is suggested that intercellular as well as intracellular movement of PVX involves a membrane-mediated process.

Management of posterior capsule rupture during phacoemulsification using the dry technique

To manage posterior capsule rupture during phacoemulsification, we use a dry technique in which all procedures are performed without an irrigation/aspiration system. The dry technique is characterized by (1) continuous viscoelastic injection instead of fluid irrigation to maintain anterior chamber depth with the posterior capsule and vitreous located posteriorly and (2) static removal of most residual lens material by viscoexpression and/or manual small incision extracapsular cataract extraction without aspiration and dynamic water flow. In 16 cases of posterior capsule rupture managed using the dry technique, the residual nucleus and cortex were readily removed with minimum extension of the ruptured area and new vitreous loss. Although large amounts of viscoelastic material (mean 5.8 mL) were required, rapid and stable visual recovery was comparable to that in patients having uneventful surgery. The dry system is a safe and reliable technique for managing posterior capsule rupture during phacoemulsification.

Tobamoviral movement protein transiently expressed in a single epidermal cell functions beyond multiple plasmodesmata and spreads multicellularly in an infection-coupled manner

Cell-to-cell movement of a plant virus requires expression of the movement protein (MP). It has not been fully elucidated, however, how the MP functions in primary infected cells. With the use of a microprojectile bombardment-mediated DNA infection system for Tomato mosaic virus (ToMV), we found that the cotransfected ToMV MP gene exerts its effects in the initially infected cells and in their surrounding cells to achieve multicellular spread of movement-defective ToMV. Five other tobamoviral MPs examined also transcomplemented the movement-defective phenotype of ToMV, but the Cucumber mosaic virus 3a MP did not. Together with the cell-to-cell movement of the mutant virus, a fusion between the MP and an enhanced green fluorescent protein variant (EGFP) expressed in trans was distributed multicellularly and localized primarily in plasmodesmata between infected cells. In contrast, in noninfected sites the MP-EGFP fusion accumulated predominantly inside the bombarded cells as irregularly shaped aggregates, and only a minute amount of the fusion was found in plasmodesmata. Thus, the behavior of ToMV MP is greatly modulated in the presence of a replicating virus and it is highly likely that the MP spreads in the infection sites, coordinating with the cell-to-cell movement of the viral genome.

Guided knives

A new type of knife that enables a surgeon to easily create tunnel-shaped incisions with a prescribed depth has been developed. The knife features an incision guide, the arm of which extends just beyond the tip of the blade. The space between the blade and the arm can be set at the desired width. By moving the knife as if sliding the arm across the corneal or scleral surface, the blade can move to a certain depth from the surface. The guided knife enables even novice surgeons to easily make a self-sealing incision during cataract surgery. In addition, the innovative nature of this device seems to be applicable to many other surgeries that require a partial-thickness incision.

AHM1, a novel type of nuclear matrix-localized, MAR binding protein with a single AT hook and a J domain-homologous region

Interactions between the nuclear matrix and special regions of chromosomal DNA called matrix attachment regions (MARs) have been implicated in various nuclear functions. We have identified a novel protein from wheat, AT hook-containing MAR binding protein1 (AHM1), that binds preferentially to MARs. A multidomain protein, AHM1 has the special combination of a J domain-homologous region and a Zn finger-like motif (a J-Z array) and an AT hook. For MAR binding, the AT hook at the C terminus was essential, and an internal portion containing the Zn finger-like motif was additionally required in vivo. AHM1 was found in the nuclear matrix fraction and was localized in the nucleoplasm. AHM1 fused to green fluorescent protein had a speckled distribution pattern inside the nucleus. AHM1 is most likely a nuclear matrix component that functions between intranuclear framework and MARs. J-Z arrays can be found in a group of (hypothetical) proteins in plants, which may share some functions, presumably to recruit specific Hsp70 partners as co-chaperones.

Role of Pseudomonas aeruginosa culture filtrates in the association, invasion, and cytotoxicity against cloned cells from murine corneal epithelium and KB cells

PURPOSE

To clarify the effect of Pseudomonas aeruginosa culture filtrates on the association with, invasion into, and cytotoxicity against cloned cells from murine corneal epithelial cells and KB cells.

METHODS

Simian virus 40-transformed murine corneal epithelial (MCE) cells were established. Murine corneal epithelial cells and KB cells were infected with a protease-positive strain, IID1117 (Pa IID1117), and a protease-negative strain, IID1130 (Pa IID1130) of P. aeruginosa, and then tested for association and invasion of Pa IID1117. The cytotoxicity test was performed by incubating the cells with culture filtrate.

RESULTS

Association of Pa IID1117 with KB cells pretreated with Pa IID1130 was significantly promoted. After pretreatment with culture filtrate, invasion was more effective into MCE cells than into KB cells. When infecting bacteria (Pa IID1117) were pretreated with protease inhibitor, invasion of the bacteria into MCE cells and KB cells clearly decreased. The cellular damage induced by the culture filtrate of Pa IID1130 was greater than the damage by that of Pa IID1117.

CONCLUSION

These results suggest that association of P. aeruginosa with MCE cells and KB cells was influenced by the culture filtrates other than proteases, and that invasion of P. aeruginosa into MCE cells and KB cells was promoted by protease.

Expression of stress-response protein 60 in iritis associated with experimental autoimmune encephalomyelitis

PURPOSE

To study the expression of stress-response proteins in the inflamed iris of rats with experimental autoimmune encephalomyelitis (EAE).

METHODS

EAE was induced in Lewis rats by immunization with homogenized spinal cord of the guinea pig emulsified in complete Freund's adjuvant (CFA) (group EAE). Control rats included those immunized with only CFA (group CFA) and those that were untreated (group Normal). Immunohistochemical study for the localization of stress-response protein (srp) 27, srp 60, srp 72, ubiquitin, and alphaB-crystallin was performed.

RESULTS

All rats in group EAE developed iritis, whereas none of the rats in group CFA and group Normal developed iritis. No expression of ubiquitin, alphaB-crystallin, srp 27, srp 60, or srp 72 was seen in the epithelium of the iris in group CFA rats. In the eyes of rats in group EAE, srp 60 was expressed in the epithelium of the iris in 20 of 22 (90.9%), ubiquitin in 4 of 22 (18.2%), and alphaB-crystallin in 3 of 22 (13.6%). In the group Normal rats, only ubiquitin was expressed in the epithelium of the iris in 1 of 6 (16.7%) eyes examined.

CONCLUSIONS

These results suggest that srp 60 may be a potential uveitogenic antigen in the iris in EAE.

Expression of stress-response protein 60 in lens epithelial cells in atopic cataract

PURPOSE

To clarify the pathogenesis of atopic cataract, especially to determine if there is any relationship between autoimmunity and atopic cataract.

METHODS

We investigated the lens epithelia obtained at surgery from 12 patients (12 eyes) with atopic cataract: from 8 patients (8 eyes) with nonatopic cataract (5 with senile cataract, 2 with juvenile cataract, and one with secondary cataract due to anterior uveitis); and from 4 autopsy eyes as controls.

RESULTS

Histopathological findings in the lens epithelial cells from atopic and nonatopic cataract patients were essentially the same: atrophy of the cells, presence of the superimposed cells, migration of cells into the lens cortex, cytoplasmic vacuolation, and loss of cells. In an immunohistochemical study, the expression of stress-response protein 60 (srp 60), srp 27, and srp 72 was examined in the lens epithelial cells. In atopic cataract specimens, 71%-87% of the lens epithelial cells were stained with the antibody against srp 60, but the cells in nonatopic cataract and control specimens were not stained.

CONCLUSIONS

Srp 27 and srp 72 were not expressed in any observed epithelial cells. The expression of srp 60 may reflect a protective mechanism of the epithelial cells against injury triggered by immunorelated agents. These findings suggest that the pathogenesis of degeneration of the lens epithelial cells in patients with atopic cataract may be related to autoimmunity.

Cyclic 3',5'-guanosine monophosphate synthesis induced by atrial natriuretic peptide, C-type natriuretic peptide, and nitric oxide in the rat retina

This study was undertaken to determine whether pathways exist in the rat retina for atrial natriuretic peptide (ANP)-, C-type natriuretic peptide (CNP)-, and nitric oxide (NO)- cyclic 3', 5'-guanosine monophosphate (cGMP). Exposure of the retina to ANP (10(-7) mol/L), CNP (10(-7) mol/L), S-nitroso-N-acetylpenicillamine (10(-5) mol/L, SNAP; a NO donor), A23187 (10(-5)mol/L; a Ca2+ ionophore), and carbachol (10(-3) mol/L) caused 1.45 approximately 1.67-fold increases in cGMP content (P < .01). The increase in cGMP content induced by A23187 was blocked by 2-4-carboxyphenyl . 4455-tetramethyl imidazoline 1-oxyl 3-oxide (10(-3) mol/ L, carboxy-PTIO; a NO scavenger). Both carboxy-PTIO (10(-3) mol/L) and NG-nitro-L-arginine (10(-3) mol/L, L-NNA: a NO synthase inhibitor) blocked the increase in cGMP content induced by carbachol. Atropine (10(-50 mol/L; a muscarinic receptor antagonist) also blocked the cGMP increase induced by carbachol. These data demonstrate that ANP-, CNP-, and NO-cGMP pathways exist in the rat retina and that the NO-cGMP pathway may be linked to the activation of the muscarinic receptor.

Laparoscopic “en-bloc” ligation of spermatic veins

Laparoscopic varicocelectomy is suggested only for II-III grade bilateral varicocele. The optical magnification granted by videosurgical techniques, prevents damaging testicular arteries; this possibility, however, requires a considerable amount of time. We performed a laparoscopic “en-bloc” ligation without sparing the artery on 13 patients with bilateral varicocele in order to assess eventual changes in gonadal volume. 10 patients underwent bilateral “en-bloc” ligation of spermatic vessels with an average operating time of 21 minutes. In 3 other patients, “en-bloc” ligation was performed on the right side while on the left side the artery was identified and saved; in these cases the average operating time was 33 minutes. After an average follow-up period of 19 months no cases of testicle atrophy nor of hydrocele were reported. ColorDoppler sonography, performed 3 months later on the 10 patients treated by bilateral “en-bloc” ligation, showed no persistent reflux. No case of homolateral persistent reflux was encountered in the 3 patients who underwent only right-side “en-bloc” ligation, but on the left side, where selective ligation had been performed, persistence of reflux was registered in one patient. Our experience has confirmed that laparoscopic “en-bloc” ligation of the internal spermatic pedicle, sparing vasa deferentia, prevents the persistence of reflux in all cases and allows a reduction in operating time. The opportunity of treating a pathology like bilateral varicocele by means of laparoscopy, which requires general anaesthesia, needs further confirmation and a larger number of case histories.

Correction of stress urinary incontinence: laparoscopy combined with vaginal suturing

The authors review the published techniques of laparoscopic colposuspension combined with vaginal suturing. Particular emphasis is given to their own technique, first published in 1992, and to that of Harewood (1993), which is similar. Both involve a Burch-like colposuspension using a technique similar to that of Gittes and Loughlin. This is possible looking inside the pelvis through a laparoscope and using a handle-needle. Published results are similar (about 70% success rate), but the authors point out that the Breda technique is simpler, cheaper, and less time consuming (only one trocar instead of three) and has had a longer follow-up (up to 3 years instead of 19 months). The authors review many other similar techniques reported between 1993 and 1995 with good results but based on rather limited experience. The conclusion is that the laparoscopic technique with vaginal suturing seems a promising way to approach stress urinary incontinence in the female patient.

Laparoscopic nephrectomy: Our personal experience on 39 cases

The authors, six years after the first laparoscopic nephrectomy by Clayman and five years after their own first case in Italy, review the literature and their personal experience in 39 cases. In their opinion, today's situation can be summed up by the conclusion that laparoscopic nephrectomy for benign disease is a safe, reproducible, cost-effective procedure and can be recommended as the procedure of choice for young ladies with a small, afunctional kidney. The same is not true for malignant diseases which, in the authors’ opinion, must be a matter for prospective, randomised and well-controlled clinical trials in reference centres.