Mobility transition of solid rare gases in confined environments

We report the results of x-ray diffraction and small angle scattering studies of Ar and Kr confined in sol-gel and Vycor glasses. The confined liquid crystallizes in a disordered hcp structure on freezing. Upon further cooling a sharp transition occurs at a reduced temperature of T/T(m) approximately 0.65, where the crystalline structure disappears and the total scattering decreases. This behavior marks the onset of a well-defined mobility transition, where the confined sample migrates out of the pore space.

Successful treatment of retrograde ejaculation with sperm recovered from bladder washings. A report of two cases

BACKGROUND

Retrograde ejaculation causes < 2% of male infertility but is the leading cause of aspermia. The incidence of retrograde ejaculation is increasing due to the aggressiveness of modern urologic cancer surgery and an increase in diabetes mellitus. Generally, the only adverse effect is on fertility. Various approaches have been proposed for treatment, ranging from insemination with sperm-rich urine obtained after masturbation to intracytoplasmic sperm injection (ICSI). We used a protocol involving bladder washing.

CASES

Case 1 involved a man with retrograde ejaculation secondary to a successful right orchiectomy and retroperitoneal lymph node dissection for stage B1 embryonal cell carcinoma. He was treated with bladder washing and intrauterine insemination. He fathered three children from six insemination cycles. Case 2 involved a man with idiopathic retrograde ejaculation and a wife with ovulatory dysfunction. He received treatment similar to that in case 1 and fathered one child from two insemination cycles.

CONCLUSION

Larger studies need to be done specifically comparing treatments. Our method resulted in four normal infants in two couples over eight total insemination cycles and, taken together with other results from the literature, seems a good choice for clinicians who are treating retrograde ejaculation for the first time. We agree with others who have recommended that in vitro fertilization/ICSI not be the first step for treating the usual couples with retrograde ejaculation.

Gamete intrafallopian transfer. A cost-effective alternative to donor oocyte in vitro fertilization in women aged 40-42 years

OBJECTIVE

To investigate whether gamete intrafallopian transfer (GIFT) may be a cost-effective alternative to donor oocyte procedures in women 40 and older with good ovarian reserve.

STUDY DESIGN

Retrospective review of records at an infertility clinic in a large multispecialty group practice. Twenty two consecutive women aged 40 and older underwent 24 stimulation cycles for laparoscopic GIFT procedures from 1988 to 1997.

RESULTS

The mean GIFT cycle cost was $5,731. The delivery rate per stimulation cycle was 25.0%. The patients who gave birth were 40-42 years of age. The mean cost per delivered infant was $22,924. A previously reported value for mean cost per pregnancy for donor oocyte in vitro fertilization (IVF) was $30,457. Theoretical costs per delivery, generated from Society for Assisted Reproductive Technology outcome data for anonymous donor oocyte IVF in 1994 (delivery rate per transfer, 34.4%) for $8,000, $9,000 and $10,000 cycle costs were $23,256, $26,163 and $29,070, respectively.

CONCLUSION

In women with good ovarian reserve, GIFT may be a cost-effective alternative to donor oocyte IVF at age 40-42.

Improving the cost-to-benefit ratio of in-vitro fertilization

In-vitro fertilization (IVF) has been criticized for being too costly to permit ready access to needy patients, either through their own funds or through those of third party providers. European groups have managed to offer these procedures at a fraction of the cost incurred by their United States counterparts by streamlining their protocols. Accordingly, we present our methods for reducing the cost of IVF. The main modification was made by performing the IVF procedures in the clinic under i.m. analgesia, avoiding the costs of a surgery suite and anaesthesia. In addition, donor, oocyte, micromanipulation, and cryopreservation services were not offered, reducing overall personnel and equipment costs. Overall costs were reduced from customary levels of $7,000--$11,000 in the United States to $3,409 per cycle initiated, while maintaining good ongoing/delivered pregnancy rates (30.0% versus 18.6% nationally) per cycle reaching aspiration. We conclude that, through the elimination of less necessary and/or utilized procedures, IVF may be performed in a more cost-effective manner while maintaining good success rates. For the patients who desire IVF services not offered under such a system, referral to a more specialized IVF center is appropriate.

Wave-front interpretation with Zernike polynomials

Several low-order Zernike modes are photographed for visualization. These polynomials are extended to include both circular and annular pupils through a Gram-Schmidt orthogonalization procedure. Contrary to the traditional understanding, the classical least-squares method of determining the Zernike coefficients from a sampled wave front with measurement noise has been found numerically stable. Furthermore, numerical analysis indicates that the so-called Gram-Schmidt method and the least-squares method give practically identical results. An alternate method using the orthogonal property of the polynomials to determinem their coefficients is also discussed.

Talbot interferometer for radial and lateral derivatives

The theory and experimental evidence of a shearing interferometer based on the Talbot effect are presented. Multiple-shearing interferences are obtained that can be reduced to triple-shearing or doubleshearing interferences by the addition of simple spatial filtering. When the shear is less than the width of the details in the object, these interferences become either the second or first derivative of the object under test, respectively. Either lateral or constant radial shear can be introduced by choosing Ronchi rulings or circular gratings. Thus both lateral and radial derivatives are easily obtained. If white light is used as a source, color fringes of high contrast are observed.