Photo thermal effect graphene detector featuring 105 Gbit s-1 NRZ and 120 Gbit s-1 PAM4 direct detection.

One of the main challenges of next generation optical communication is to increase the available bandwidth while reducing the size, cost and power consumption of photonic integrated circuits. Graphene has been recently proposed to be integrated with silicon photonics to meet these goals because of its high mobility, fast carrier dynamics and ultra-broadband optical properties. We focus on graphene photodetectors for high speed datacom and telecom applications based on the photo-thermo-electric effect, allowing for direct optical power to voltage conversion, zero dark current, and ultra-fast operation. We report on a chemical vapour deposition graphene photodetector based on the photo-thermoelectric effect, integrated on a silicon waveguide, providing frequency response >65 GHz and optimized to be interfaced to a 50 Ω voltage amplifier for direct voltage amplification. We demonstrate a system test leading to direct detection of 105 Gbit s-1 non-return to zero and 120 Gbit s-1 4-level pulse amplitude modulation optical signals.

Manipulation and generation of supercurrent in out-of-equilibrium Josephson tunnel nanojunctions.

We demonstrate experimentally the manipulation of supercurrent in Al-AlOx-Ti Josephson tunnel junctions by injecting quasiparticles in a Ti island from two additional tunnel-coupled Al superconducting reservoirs. Both supercurrent enhancement and quenching with respect to equilibrium are achieved. We demonstrate cooling of the Ti line by quasiparticle injection from the normal state deep into the superconducting phase. A model based on heat transport and the nonmonotonic current-voltage characteristic of a Josephson junction satisfactorily accounts for our findings.

Mycophenolate mofetil pharmacokinetic monitoring in pediatric kidney transplant recipients.

This open-label, longitudinal, long-term study of de novo pediatric renal transplant recipients was designed to investigate the pharmacokinetics (PK) of mycophenolic acid (MPA) and its possible interaction with cyclosporine (CsA). Thirty-four children on an immunosuppressive regimen of CsA, prednisone, and mycophenolate mofetil (MMF, 300-400 mg/m2 twice daily) were investigated at 6, 30, 180, and 360 days after transplantation. Considerable interindividual variability in the areas under the concentration curve (AUC(0-12)) of MPA was observed during the follow-up, although the dose of MMF remained the same over the same time. Predose levels (C0) increased significantly during the first 6 months after transplantation: C0 at 6 and 180 days after transplantation was 0.8 +/- 0.6 and 1.9 +/- 1.1 microg/mL (P < .0001). A significant time-dependent increase in the AUC of MPA was also observed during the first 6 posttransplant months: AUC(0-12) at 6 and 180 days after transplantation was 23.3 +/- 10.8 and 40 +/- 11.6 mg*h/L (P = .003). MPA concentrations 3 and 4 hours after MMF intake were the individual time points that best correlated with the full MPA AUC (r = 0.8 and 0.79; P < .001). The abbreviated MPA AUC (0-4 hours) correlated reasonably with the full AUC (r = 0.87; P < .001). Finally, a significant reduction in CsA dose during the first 6 posttransplant months (P < .001) matched the significant increases in both MPA C0 and full MPA AUC, thus demonstrating the interaction of the 2 immunosuppressive drugs. These observations suggest the need for therapeutic drug monitoring when adjusting the dose of MMF in children.

Cyclosporine monitoring in stable, long-term, pediatric kidney transplant recipients: the value of C2 determination.

Although a generalized consensus has been reached for therapeutic drug monitoring of cyclosporine microemulsion in adult transplant patients, clear guidelines are recently not available for the pediatric population. In this retrospective analysis of pharmacokinetic data obtained from stable, long-term, pediatric kidney transplant recipients, we sought to define a possible approach to manage cyclosporine therapy in a pediatric setting. The 2-hour postdose cyclosporine blood concentration, C(2), rather than trough levels, was the best single time point predictor of the area under the concentration curve. We concluded that therapeutic drug monitoring of cyclosporine-based immunosuppressive regimens should be tailored based on C(2) determinations for pediatric kidney transplant recipients.

The captopril test in children with renovascular and renal hypertension.

We used the captopril test (CT) in 32 children, 8 with renovascular hypertension (RVH), 17 with renal hypertension (RH) and 7 with normal blood pressure, in order to study the renin-angiotensin system activation (RASA). All children affected by RVH presented a positive CT: a post-captopril plasma renin activity (PRA) of 12 ng ml-1 h-1 or more, an absolute PRA increase of 10 ng ml-1 h-1 or more and a 150% increase or more, or 400% or more if the baseline PRA was less than 3 ng ml-1 h-1. The CT may be useful for demonstrating the RASA in RVH.

B7-1 amplifies the response to interleukin-2-secreting tumor vaccines in vivo, but fails to induce a response by naive cells in vitro.

Parental and interleukin-2 (IL-2)-secreting CMS5 tumor cells were transfected with the B7-1 costimulatory molecule to amplify anti-tumor responses. CMS5 cells transfected with B7-1 grew more slowly in vivo than did parental CMS5 cells. Moreover, tumor cells secreting levels of IL-2 too low to cause rejection alone were rejected following transfection with B7-1. To determine whether the expression of B7-1 enabled the tumor cells to activate T cells directly, their ability to stimulate in vitro functional responses by T cells was examined. We found that neither B7-1+ nor IL-2-secreting, B7-1+ CMS5 cells stimulated naive spleen cells to proliferate or to become cytotoxic. In contrast, restimulation of primed T cells by B7-1+ CMS5 cells resulted in stronger cytotoxicity responses than seen following restimulation by parental CMS5 cells. Lysis was even higher if the B7-1+ tumor cells also secreted IL-2. Our results suggest that the expression of costimulatory molecules can augment responses generated by vaccinating with IL-2-secreting tumor cells. Furthermore, they are consistent with the hypothesis that the initiation of an anti-tumor response by naive T cells may depend upon initial antigen presentation by another unidentified cell and that the major action of IL-2-secreting and/or B7-1+ tumor cell vaccines might be to potentiate the response of already primed cells.

Influence of spermatozoa characteristics on gamete intra-fallopian transfer procedures: analysis of results obtained utilizing normozoospermic, oligoasthenozoospermic and donor spermatozoa.

The objective of this study was to analyze the efficacy of the gamete intra-Fallopian transfer (GIFT) procedure in relation to spermatozoa characteristics. A total of 268 infertile couples enlisted for GIFT were categorized into three groups on the basis of semen characteristics in the husband. These included oligoasthenozoospermic men in 88 retrieval cycles (group 1), normozoospermic men in 116 cycles (group 2) and azoospermic partners who needed donor semen in 86 cycles (group 3). All female patients had ovarian stimulation and laparoscopic GIFT. Pregnancy rates were significantly higher with donor spermatozoa than with oligoasthenozoospermic or normozoospermic spermatozoa, i.e. 51.1% versus 15.9% (P < 0.001), and 32.7% (P < 0.005). Implantation rates were significantly higher with donor spermatozoa than with normo- or oligoasthenozoospermic spermatozoa (P < 0.01). These data suggest that GIFT does not give good results with male factor infertility. Donor cryopreserved semen gives higher pregnancy and implantation rates than normozoospermic semen, and GIFT with donor spermatozoa gives a good chance of pregnancy to couples previously treated with artificial insemination using donor semen.

[Frequency of microalbuminuria in an adult population]. / Frequenza della microalbuminuria nella popolazione adulta.

Urinary samples overnight collected from the thousand normotensive adults with normal urinalysis and normal serum levels of creatinine, urea and glucose were tested for the presence of microalbuminuria by latex test Sclavo. Fourty-five cases were positive: the values of microalbuminuria in 21 of these cases tested with RIA method exceeded 26 mg/l; one hundred twenty-six latex-negative cases evidenced lower RIA values. The high sensitivity of the test and its clinical significance suggest the need of an automatic procedure for detecting microalbuminuria in Albustix-negative urine samples.

Persistent tubular resistance to aldosterone in infants with congenital hydronephrosis corrected neonatally.

Renal function of 18 infants who had undergone surgery in the neonatal period because of severe congenital hydronephrosis was followed up for 5 to 36 months (mean +/- SD 21 +/- 10 months). In all cases the diagnosis was made prenatally by sonography and confirmed at birth by intravenous urography. Creatinine clearance developed normally in all the children. Eight had a reduction in maximal urinary concentrating ability after intranasal DDAVP; this defect was transient and resolved after 4 to 5 months in all but one child, in whom it persisted. However, other tubular abnormalities were present. Throughout the observation period, patient serum potassium concentrations were significantly higher than normal, paralleled by a significant increase in plasma aldosterone concentration but with normal excretion fraction of sodium and potassium. There were no disturbances of acid-base balance. These findings may be accounted for by a persistent partial reduced sensitivity of the distal tubule to the action of aldosterone despite normal renal function. This alteration is usually mild, but may constitute a persistent metabolic risk despite successful surgical intervention.

Early childhood hyperkalemia: variety of pseudohypoaldosteronism.

Fractional excretion of electrolytes, renal acidification capacity and the renin-aldosterone system have been studied in 5 non-azotemic children, 19-25 months old, with mineralocorticoid resistant hyperkalemia, discovered in the first month of life. Although fractional potassium excretion was similar in patients and in a group of control healthy children (13.8 +/- 5.2% vs. 8.7 +/- 6.4%) it was inappropriately low in the patients for their higher potassium concentration. Fractional sodium excretion was significantly increased in the patients (1.6 +/- 0.3% vs. 0.67 +/- 0.4, p less than 0.02). Normal net acid and ammonium excretion and intact ability to lower urinary pH during acid loading were observed in all patients. Mean values for plasma aldosterone (37.0 +/- 9.1 vs. 13.9 +/- 11.2 ng/dl), plasma renin activity (12.5 +/- 3.9 vs. 8 +/- 2.8 ng/ml/h) and plasma aldosterone/plasma potassium ratio (7.11 +/- 1.5 vs. 3.08 +/- 1.7) were higher in the patients than in the control subjects (all p less than 0.001). These data support the hypothesis that a partial lack of response of the renal tubule to endogenous mineralocorticoids was present in the patients. This type of pseudohypoaldosteronism is less severe than that described for the classic form and for early childhood renal acidosis.

A comparison of the delta copper T and the copper T 200 in Bologna, Italy.

An analysis is presented of a comparative study of the Delta T and Copper T 200 IUDs. A total of 195 postabortion insertions was performed between March 1981 and August 1982. All insertions were performed with an inserter. Primary bleeding/pain complaints after insertion were largely related to intermenstrual problems, with spotting the most frequently reported. Nine women had their devices removed for PID. One pregnancy occurred at ten months in the Delta T group. Both groups had one expulsion/displacement. Eight devices in each group were removed for bleeding/pain. Two women in the TCu group had their devices removed for personal reasons. The 6-months continuation rates for the two groups were 85.5 for the Delta T group and 82.2 for the TCu group. The 6-months follow-up rate for the Delta T group was 39.4 and 38.8 for the TCu group.

PIP: Complications associated with postabortion insertion of the Delta T and Copper T 200 IUDs were compared in 195 women. All insertions were performed with an inserter. There were no reported incidents of inserter-related problems, pelvic pain, or other complications at insertion. At follow-up, intermenstrual spotting was the most frequently reported complaint, involving 14 women (18.2%) in the Delta T group and 7 women (9.5%) in the TCu group. 8 Delta T acceptors (10.4%) and 12 TCu acceptors (16.2%) experienced intermenstrual bleeding. Intermenstrual pain was reported by 7 (9.1%) Delta T users and 4 (5.4%) TCu users. Other primary bleeding and pain complaints included menorrhagia, reported by 9 (11.7%) Delta T users and 9 (12.2%) TCu users, and dysmenorrhea, reported by 5 (6.5%) Delta T users and 4 (5.4%) TCu users. Pelvic inflammatory disease (PID) confined to the uterus was diagnosed in 9 (11.7%) Delta T acceptors and 5 (6.8%) TCu acceptors. 7 women (9.1%) in the Delta T group and 8 women (10.8%) in the TCu group reported PID confined to the adnexa. 1 woman from each group had PID confined to the uterus and adnexa and 5 TCu users reported PID beyond the uterus and adnexa. Of the 36 women diagnosed with PID, 9 had their devices removed. There was 1 pregnancy in the Delta T group and 1 device from each group was expelled. There were 3 removals for pain and bleeding in the Delta T group and 4 removals for this reason in the TCu group. The 6-month continuation rate was 85.5 for the Delta T device and 82.2 for the TCu IUD. Given the high incidence of spotting, intermenstrual bleeding, and PID recorded in this sample, insertion of an IUD in the immediate postabortion period is not recommended.

Neurochemical effects of minaprine, a novel psychotropic drug, on the central cholinergic system of the rat.

Minaprine, a novel psychotropic drug with antidepressant, anticataleptic and antiaggressive properties, produced an increase in rat brain regional acetylcholine content at a subconvulsant dose of 30 mg/kg IP. The greatest increase (60%) was produced in the striatum, whereas an increase of about 35% was obtained in the hippocampus and the rest of the cortex. A small but significant increase of 14% was also found in the midbrain-hindbrain region. Minaprine decreased choline content only in the striatum. No tolerance to acute challenge was observed after 10-day chronic treatment. In vitro, the drug had no effect on striatal choline acetyltransferase activity up to a concentration of 160 microM and only weakly displaced (3H) dexetimide from its specific muscarinic receptor binding sites in striatum (IC50, 2 X 10(-4) M). After in vivo administration the drug did not affect sodium-dependent high affinity choline uptake by a hippocampal homogenate. On the other hand, the drug inhibited both striatal and hippocampal acetylcholinesterase activity at high (40-160 microM) concentrations in vitro. In vivo the drug produced a brief (5 min), small (18%) decrease in the enzymic activity which corresponded in time to the peak drug level attained in the brain, but was not concomitant with a change in striatal acetylcholine content. By contrast, the increase in striatal acetylcholine appeared after 30 min when there was no longer inhibition of acetylcholinesterase activity and when the level of minaprine in brain was reduced by 78%. Blockade of dopamine receptors by pimozide pretreatment partially prevented the increase in striatal acetylcholine produced by minaprine, whereas interference with cholinergic or serontonergic neurotransmission was without effect.(ABSTRACT TRUNCATED AT 250 WORDS)