Common variant at 16p11.2 conferring risk of psychosis.

Epidemiological and genetic data support the notion that schizophrenia and bipolar disorder share genetic risk factors. In our previous genome-wide association study, meta-analysis and follow-up (totaling as many as 18 206 cases and 42 536 controls), we identified four loci showing genome-wide significant association with schizophrenia. Here we consider a mixed schizophrenia and bipolar disorder (psychosis) phenotype (addition of 7469 bipolar disorder cases, 1535 schizophrenia cases, 333 other psychosis cases, 808 unaffected family members and 46 160 controls). Combined analysis reveals a novel variant at 16p11.2 showing genome-wide significant association (rs4583255[T]; odds ratio=1.08; P=6.6 × 10(-11)). The new variant is located within a 593-kb region that substantially increases risk of psychosis when duplicated. In line with the association of the duplication with reduced body mass index (BMI), rs4583255[T] is also associated with lower BMI (P=0.0039 in the public GIANT consortium data set; P=0.00047 in 22 651 additional Icelanders).

Quetiapine fumarate for schizophrenia and bipolar disorder in young patients.

During the past decade, there has been a substantial increase in the prescribing of antipsychotics to young patients for a variety of pediatric psychiatric disorders. Quetiapine (Seroquel®) received its initial indication from the U.S. Food and Drug Administration for treatment of schizophrenia in 1997, and it received its second indication for the treatment of mania-associated bipolar disorder in 2004. Currently, in young patients, authorized quetiapine indications are schizophrenia in individuals aged 13 or older and manic episodes associated with bipolar I disorder in children 10 to 17 years old. Quetiapine has different pharmacological actions and acts as an antagonist for following receptors: D(2) receptor, serotonin 5-HT(2A) also known as α(1)-adrenoceptor, histamine 1 receptor and muscarinic acetylcholine receptor. Several studies have shown its favorable profile of effectiveness and tolerability in young bipolar and schizophrenic patients. However, the current data make it very clear that the risks and benefits of this drug need to be weighed individually for each patient.

Revascularization of unprotected left main coronary artery disease with percutaneous coronary intervention: the role of drug-eluting stents.

The percutaneous revascularization of left main coronary artery stenosis has until recently been reserved for patients at prohibitive surgical risk or for selected emergent cases. This adopted practice of coronary artery bypass grafting, as the standard of care for left main coronary artery stenosis, has largely occurred secondary to disappointing results with bare metal stents implanted in the left main coronary artery. However, in the current era of drug-eluting stents (DES) which significantly reduce restenosis compared to bare metal stents, there has been a renewed interest in examining the role of percutaneous coronary intervention as a means of revascularization of left main disease. This article discusses recent and ongoing studies investigating the role of percutaneous intervention of left main disease, with an emphasis on the use of DES for this purpose.

Space-time coupling and collapse threshold for femtosecond pulses in dispersive nonlinear media.

Femtosecond space-time coupling effects in dispersive nonlinear media are investigated by a simple approximate method. The applicability of the method is verified by comparison with earlier numerical simulations. New results are presented for astigmatic beams as well as for negative dispersion. The position of the beam waist in the material changes the collapse threshold. For astigmatic beams, collapse is prevented for pulse durations shorter than a critical value.

Self-starting mode locking of a cw Nd:YAG laser using cascaded second-order nonlinearities.

The nonlinear mode variations induced by the equivalent third-order susceptibility resulting from cascaded secondorder nonlinearities in an intracavity lithium triborate crystal are exploited for mode locking of a cw Nd:YAG laser. The loss modulations are provided by a slit, as in the Kerr-lens mode-locking scheme. The mode-locking process is self-starting and produces nearly transform-limited pulses of 14-ps duration with 0.5-W average power.

Continuous-wave mode locking of a bulk erbium-ytterbium glass laser.

Continuous-wave mode-locking operation of a bulk Er:Yb:phosphate glass laser, pumped by either a Ti:sapphire or an InGaAs diode laser, is reported for what is to our knowledge the first time. Pulses with a 90-ps duration, a 100-MHz repetition rate, and as much as 7-mW average power have been obtained.

Nonlinear mirror mode locking of a cw Nd:YLF laser.

Passive mode locking of a cw lamp-pumped Nd:YLF laser with the nonlinear mirror technique is reported. Nearly transform-limited pulses of 13-ps duration and 1.5-W average power at 1.047 microm have been obtained. The nonlinear mirror consists of a lithium triborate frequency-doubling crystal and a dichroic mirror with high reflectivity for the second harmonic and lower reflectivity for the fundamental frequency. The mode-locking process is self-starting, with pulse duration and stability strongly dependent on the cavity parameters.

Resonators for Kerr-lens mode-locked femtosecond Ti:sapphire lasers.

Resonators for Kerr-lens mode-locked lasers are studied with the help of an analytical model, and a new design procedure is presented. The experiments performed with a femtosecond Ti:sapphire laser demonstrate that this model permits an effective resonator design and offers reliable guidelines for the final experimental optimization. With a suitable resonator configuration, self-starting of the Kerr-lens mode-locking regime has been achieved.

Self-starting Kerr-lens mode locking of a Ti:sapphire laser.

It is shown that Kerr-lens mode locking of a Ti:sapphire laser, with no intracavity elements except the laser rod and the dispersion-compensating prisms, can be made to be completely self-starting. We achieve this result by carefully designing the resonator to maximize the nonlinear mode variations and dynamic loss modulation.

Highly efficient parametric conversion of femtosecond Ti:sapphire laser pulses at 1 kHz.

Pulses with energies as high as 150 microJ and durations as low as 60 f(s) were generated from 1.1 to 2.6 microm by a traveling-wave parametric converter pumped by femtosecond pulses of a Ti:sapphire laser with chirped-pulse amplification.

Q-switched Nd:YAG laser with super-Gaussian resonators.

An unstable resonator that uses radially variable-reflectivity mirrors of super-Gaussian profile has been used in a Nd:YAG laser in the Q-switching regime. Three reflectivity profiles, corresponding to different super-Gaussian orders, have been tested. The output energy increases with the super-Gaussian order and can be higher than that of a traditional stable multimode resonator. The output beams are diffraction limited, showing only moderate spreading of energy out of the central lobe in the far field.

Diode-pumped cw bulk Er:Yb:glass laser.

ontinuous-wave laser operation of bulk Er:Yb:phosphate glass pumped at 980 nm by an InGaAs index-guided diode laser has been achieved for the first time to our knowledge, with 2 mW of output power obtained at 1.54 microm. To optimize pumping conditions and to investigate the effects of pump wavelength, the Er(3+):Yb(3+) glass disk has also been pumped by a Ti:Al(2)O(3) laser at 960 and 980 nm, and we obtained high output power (70 mW) and the highest slope efficiency (21% for 980-nm pumping) reported to date for a bulk Er:glass laser.

Anaesthesia for emergency caesarean section.

The Report on Confidential Enquiries into Maternal Deaths in England and Wales 1982-84 (Department of Health 1989) recommends early involvement of the anaesthetist in women having emergency caesarean sections and the use of epidural anaesthesia in preference to general anaesthesia. In an observational prospective study the need for emergency abdominal delivery could be anticipated in 87% of 360 consecutive emergency caesarean sections. Early establishment of epidural analgesia allowed extension, to an appropriate level for the surgery, in 70%. The duty anaesthetist accompanying the obstetric team on three wardrounds a day could be forewarned of anticipated problems in most women who are eventually delivered abdominally.

Optical coatings with variable reflectance for laser mirrors.

Design procedures and fabrication techniques of variable reflectance dielectric mirrors for laser output couplers are proposed. The design criteria, based on the use of only one shaped layer in a multilayer structure, yield any peak value and shape of the reflectance profile. The deposition technique of the variable thickness layer consists of a sputtering process with a suitable mask interposed between the target and substrate. Results of a simple model that correlates the mirror parameters to mask diameter and position are presented. A few devices for a Nd:YAG laser have been proposed, characterized, and successfully tested in a laser resonator.

Modes of resonators with mirror reflectivity modulated by absorbing masks.

The modes of a stable laser resonator containing, near one mirror, an absorbing mask with two apertures have been calculated on the basis of scalar diffraction theory and experimentally observed in a pulsed Nd:YAG laser. The mode structure has been investigated as a function of the mask geometry, and an interpretation in terms of supermodes is provided.

Unstable laser resonators with super-Gaussian mirrors.

A new class of tapered reflectivity mirrors with a super-Gaussian profile R infinity exp(-kr(n)) is introduced, and a geometrical-optics approach for analysis and design of unstable resonators made with these mirrors is presented. A super-Gaussian mirror, built by a special evaporation technique, has been tested in an unstable resonator of a pulsed Nd:YAG laser, demonstrating its effectiveness in generating diffraction-limited beams.