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Nondestructive testing (NDT) and imaging of materials with unknown properties are important applications of terahertz technology. Different contrast-forming methods are available to obtain diverse information on the imaged region, including intensity, color, phase, and polarization. Polarimetric imaging is relatively under-investigated owing to the difficulty in its implementation with complex optical arrangements. In this article, we present the design and monolithic fabrication of an anisotropic metasurface that incorporates several beam-forming functions in a single layer with high efficiency thus simplifying instrument construction. The probe beam generated by the metasurface consists of an orthogonally polarized pair of collinear Bessel beams that create a well-defined on-axis change of polarization. The metasurface is integrated into a polarimetric imaging microscope for 3-D beam profiling and sensing experiments at 2.52 THz. An analytical model to describe the on-axis polarization variation was found to be in excellent agreement with both finite-difference time-domain (FDTD) simulations and the experimental results. The setup was used to measure the refractive index and diattenuation of homogeneous sample regions in a proof-of-principle application. We anticipate this technology will find future applications in NDT and polarimetric imaging of polymer composites and 3-D profilometry of reflective surfaces.

AbstractAimsTo develop a model to evaluate the cost-effectiveness of 4 mg dibotermin alfa/absorbable collagen sponge (ACS) versus iliac crest bone graft (ICBG) in patients with lumbar degenerative disc disease in the United Kingdom.Materials & methodsA Markov decision-analytic model was constructed to calculate costs and quality-adjusted life-years over a 4-year time horizon in each treatment group, from a United Kingdom National Health Service perspective. An individual patient data meta-analysis was undertaken to synthesize data from four randomized controlled trials and two single-arm studies concerning health-related quality of life and procedural resource use. Current cost data from the United Kingdom were then applied to determine the overall mean cost per patient in each group. One-way and probabilistic sensitivity analyses were undertaken to explore the impact of parameter uncertainty.ResultsThe model predicted 4-year discounted cost savings of £192 per patient treated with dibotermin alfa/ACS, compared with ICBG, and a gain of 0.0114 QALYs per patient over the same time period. Sensitivity analyses indicated that the results were most sensitive to variability in the differences in health-related quality of life and secondary surgery rate, with dibotermin alfa/ACS having a 60% probability of being cost-effective at a willingness-to-pay threshold of £20,000 per QALY gained.LimitationsThere is uncertainty in the difference in cost and QALYs between the two groups. However, comprehensive sensitivity analyses were undertaken to explore this and present the results in a transparent manner.ConclusionsOur results provide an economic case for the use of 4 mg dibotermin alfa/ACS versus iliac crest bone graft, with additional health benefits predicted at reduced overall cost.

A broad linewidth and a lack of spectral analysis limit the applications of plasmonic sensors. In this Letter, a plasmonic sensor with a large sensitivity in the terahertz (THz) range is proposed based on high-quality factor (>1000) surface lattice resonance in subwavelength near-flat metallic gratings. Moreover, such a highly selective spectral manipulating scheme, plus the greatly localized plasmonic resonance, enables miniaturized spectroscopy based on a single detector by integrating an electro-optical material with the gratings. A spectral resolution of 0.1 GHz at a center frequency of 1.1 THz is predicted showing a four times improvement of measuring efficiency. This technique shows promising potential in on-site matter inspection and point-of-care testing.

As single-photon imaging becomes progressively more commonplace in sensing applications such as low-light-level imaging, three-dimensional profiling, and fluorescence imaging, there exist a number of fields where multispectral information can also be exploited, e.g., in environmental monitoring and target identification. We have fabricated a high-transmittance mosaic filter array, where each optical filter was composed of a plasmonic metasurface fabricated in a single lithographic step. This plasmonic metasurface design utilized an array of elliptical and circular nanoholes, which produced enhanced optical coupling between multiple plasmonic interactions. The resulting metasurfaces produced narrow bandpass filters for blue, green, and red light with peak transmission efficiencies of 79%, 75%, and 68%, respectively. After the three metasurface filter designs were arranged in a 64×64 format random mosaic pattern, this mosaic filter was directly integrated onto a CMOS single-photon avalanche diode detector array. Color images were then reconstructed at light levels as low as approximately 5 photons per pixel, on average, via the simultaneous acquisition of low-photon multispectral data using both three-color active laser illumination and a broadband white-light illumination source.

The need for energy efficiency and lower emissions from industrial plants and infrastructures is driving research into novel sensor technologies, especially those that allow observing and measuring greenhouse gases, such as CO_2. CO_2 emissions can be captured using mid-infrared imagers, but at present, these are based on hybrid technologies that need expensive manufacturing and require cooling. The high price tag prevents a wider diffusion of mid-infrared imagers and hence their use for many low-cost and large-volume applications. Here we report a monolithic III-V technology that integrates GaAs transistors with an InSb photodiode array. The monolithic material system reduces costs and provides an excellent platform for the sensor system-on-chip. We present a focal plane array imaging technology operating at room temperature in the 3–6 μm wavelength range that will address the need for identification and measurement of a range of industrially important gases.

This paper presents the design of an innovative, low-cost, uncooled, metamaterial-based terahertz (THz) focal plane array (FPA). A single pixel is composed of a resonant metamaterial absorber and micro-bolometer sensor integrated in a standard 180 nm CMOS process. The metamaterial is made directly in the metallic and insulating layers available in the six metal layer CMOS foundry process. THz absorption is determined by the geometry of the metamaterial absorber which can be customized for different frequencies. The initial prototype consists of a 5$\times$ 5 pixel array with a pixel size of 30 $\mu$m$\times$30 $\mu$m and is readily scalable to more commercially viable array sizes. The FPA imaging capability is demonstrated in a transmission and reflection mode experiment by scanning a metallic object hidden in a manila envelope.

The article presents information on the two new species of the bulbous perennial herb genus Ledebouria from South Africa which include the Ledebouria corrugata and the Ledebouria rietrivierensis.

Infrared plasmonic filters, consisting of subwavelength hole arrays etched into metal films, exhibit characteristics that are typically associated with the formation of surface plasmon polaritons, namely enhanced transmission and wavelength filtering of the incident light. In this article, the properties that dictate the plasmonic response of a material from the optical to the infrared regime are investigated, followed by the design, simulation, fabrication and characterisation of an infrared plasmonic filter set. Infrared plasmonic filters have also been integrated with optical plasmonic filters and a terahertz metamaterial to create a new hybrid multi‐spectral material that can filter blue, green, red, near infrared, short wave infrared and two mid infrared wavelengths whilst simultaneously absorbing a single terahertz frequency. The multi‐spectral material could be integrated with appropriate image sensors to create a multi‐spectral camera capable of operating at optical, infrared and terahertz wavebands simultaneously. In this article the properties that determine the plasmonic response of a material at optical and infrared wavelengths are investigated, followed by the design, simulation, fabrication and characterisation of an infrared plasmonic filter set. Infrared plasmonic filters have also been integrated with optical plasmonic filters and a terahertz metamaterial to create a new multi‐spectral material that can filter three optical wavelengths and four infrared wavelengths whilst simultaneously absorbing a single terahertz frequency.

In this paper, we fabricated an anisotropically etched multilevel silicon diffractive lens. The operating frequency and focal length of the lens are 2.52 THz and 15 mm, respectively. Both 4- and 16-level lenses have been realized. The total etch depth and size of the lenses are 49 μm and 45 mm × 45 mm. Positive tone thick resist AZ 4562 was used as a mask material for dry etching the high resistivity silicon substrate. We have characterized the lens using a high power continuous wave far infrared laser operating at 2.52 THz. The measured results show good agreement with the designed specifications.

A personal narrative is presented which explores the author's experience of setting up his basement woodworking shop.

Venous thromboembolism (VTE) refers to a blood clot that starts in a vein. The risk of developing VTE is highest after major surgery or a major injury, or when someone has heart failure, cancer, or infectious disease (e.g., COVID-19). Without prompt treatment to break up clots and prevent more from forming, VTE can restrict or block blood flow and oxygen, which can damage the body tissue or organs. VTE can occur without any obvious signs, and imaging technologies are used. Alternatively rapid measurement of thrombin generation (TG) and D-dimer could be used to make a fast, portable, and easy-to-use diagnostic platform for VTE. Here, we have demonstrated a diagnostic sensing platform with the ability of simultaneous detection of TG and D-dimer in human plasma. Modifications were made to both the assay protocols to eliminate the need for sample dilution and incubation steps. Using a substantially reduced sample volume, the measurement results show comparable performance to the gold standard method. Our platform is able to deliver accurate and cost-effective results for both TG and D-dimer assays when using undiluted plasma in under 15 min. The assays presented are therefore a good candidate technology for use in a point-of-care platform to diagnose VTE.

A miniaturised lab-in-a-pill device has been produced incorporating a temperature and pH sensor with wireless communication using the 433.92 MHz ISM band. The device has been designed in order to enable real time in situmeasurements in the gastrointestinal (GI) tract, and accordingly, issues concerning the resolution and accuracy of the data, and the lifetime of the device have been considered. The sensors, which will measure two key parameters reflecting the physiological environment in the GI (as indicators for disease) were both controlled by an application specific integrated circuit (ASIC). The data were sampled at 10-bit resolution prior to communication off chip as a single interleaved data stream. This incorporated a power saving serial bitstream data compression algorithm that was found to extend the service lifetime of the pill by 70%. An integrated on–off keying (OOK) radio transmitter was used to send the signal to a local receiver (base station), prior to acquisition on a computer. A permanent magnet was also incorporated in the device to enable non-visual tracking of the system. We report on the implementation of this device, together with an initial study sampling from within the porcine GI tract, showing that measurements from the lab-on-a-pill, in situ, was within 90% of literature values.

Objective:The effect of Alberta’s health reform on length of stay for maternity cases and on subsequent mothers’ rehospitalization was examined in the present study. Methods:The data set included all Alberta acute care hospital separation records from 1991/92 to 1996/97 inclusive. A logistic regression was applied to the data in order to examine the effects of prepartum condition, type of delivery, length of stay, maternal age, and year on the likelihood of readmission. Results:Health reform proved to be associated with a dramatic decrease in length of stay for maternity cases; from 3.8 to 2.4 days on average. This was accompanied by very little variation in the 90-day readmission rate for mothers over the same time period (notably, a slight decrease). Higher readmission rates were associated with the existence of difficulties during the pregnancy and other prenatal conditions, maternal age, and with the type of delivery. There were no dramatic changes in the rates for prepartum diagnoses, nor for the type of delivery. Discussion:The data suggest that the reduction in the length of maternity stay has had no discernible negative health effects on new mothers, perhaps because of the home visiting programs that were put in place. Furthermore, there may still be room to improve outcomes by focussing on those with prepartum conditions and cases involving complicated births. Objectif:Cette étude porte sur l’effet de la réforme de la santé en Alberta sur la durée du séjour à l’hôpital après l’accouchement et sur les réhospitalisations subséquentes des mères. Méthode:Nous avons étudié les données de tous les registres de sortie des hôpitaux albertains de soins actifs, de 1991–1992 à 1996–1997, inclusivement. Nous les avons analysées par régression logistique pour déterminer les effets de diverses variables (état de santé avant l’accouchement, mode d’accouchement, durée du séjour, âge maternel et année) sur la vraisemblance d’une réadmission. Résultats:La réforme de la santé était associée à une réduction considérable de la durée du séjour à la maternité, qui est passé de 3,8 à 2,4 jours en moyenne. Elle s’est accompagnée d’un très faible écart (en fait, une légère baisse) dans le taux de réadmission des mères dans un délai de 90 jours pendant la même période. Les taux de réadmission élevés étaient associés aux grossesses difficiles et autres troubles prénatals, à l’âge maternel et au mode d’accouchement. Il n’y a pas eu de changements considérables dans les taux associés au diagnostic avant l’accouchement ou au mode d’accouchement. Discussion:Ces données portent à croire que la réduction de la durée du séjour à la maternité n’a eu aucun effet néfaste évident sur la santé des nouvelles mères, peut-être en raison de la mise en place de programmes de visites à domicile. En outre, il serait encore possible d’améliorer ces résultats en mettant l’accent sur les mères dont la grossesse a été difficile et les naissances avec complications.

Objectives:To determine variations in the rate of inpatient and outpatient dilatation and curettage (D&C), for the treatment of early pregnancy loss and for the diagnosis of abnormal uterine bleeding, in 17 health regions across a Canadian province.

there is extensive literature comparing the effects of different surgical procedures used in breast cancer treatment on psychological outcome. Body image in breast cancer has received considerable research attention. Narrow views focused on the physical effects of the cancer and of competing treatments on body image have received criticism, and broader approaches are currently being advocated. In this paper, body image in breast cancer and its treatments are examined in the context of the available literature. Preliminary results of the focus group component of a recent research study into body image in breast cancer are reported. Implications for clinical practice based on a review of the literature, and on the focus group results in particular, are discussed.

Controlled ovarian hyperstimulation and sperm injection or intra-uterine insemination (COH/SI) have become important forms of treatment for unexplained and male factor infertility. An extensive literature on sperm preparation has developed (more than 2,000 papers), and the recent withdrawal of indications for human use of Percoll makes it necessary to re-examine the methods available which have been proven effective. In this paper, we have reviewed methods of sperm preparation and their applicability to intra-uterine insemination.

Recent studies have documented that women engaged in strenuous exercise programs may develop reproductive defects, including delayed menarche, shortened local phase, and amenorrhea. The etiological bases for these abnormalities have not been determined, but physical, hormonal, nutritional, psychological, and environmental factors may be involved and may differ in importance in affected individuals. The consequences of the altered reproductive function associated with exertion will not be identified until prospective long‐term investigations are conducted. In the absence of data to the contrary, however, we currently believe that exercise‐associated defects in reproduction are not serious and may he reversed by changes in life‐style.

A previous study had demonstrated the superiority of hysteroscopy over hysterosalpingography for the detection of intrauterine lesions in infertile patients. One hundred and sixty-nine patients were examined by a combined laparoscopic and hysteroscopic technique as the means of detecting tubal, peritubal, peritoneal, or intrauterine causes of infertility. Laparoscopy was successful in 168 and hysteroscopy in 162. The rate of diagnosis by laparoscopy of 49.4% was increased to 66% when the hysteroscopic findings were included. Only one serious complication was recorded, the inadvertent visualization of an intrauterine pregnancy. Arguments are advanced for the replacement of hysterosalpingography with combined laparoscopy and hysteroscopy as the primary means of investigating the ovulatory infertile female.

CUMMING, D. C, L. A. BRUNSTING, III, G. STRICH, A. L. RIES, and R. W. REBAR. Reproductive hormone increases in response to acute exercise in men. Med. Sci. Sports Exerc., Vol. 18, No. 4, pp. 369–373, 1986. The increase in serum testosterone levels generally observed with intense, short-term exercise remains unexplained since most investigators have not reported any increase in the levels of luteinizing hormone, the pituitary glycoprotein most responsible for testicular steroidogenesis. Hemoconcentration and decreased metabolic clearance have been suggested as mechanisms to explain the exercise-associated tesosterone increase. Such non-specific mechanisms should apply to other steroid hormones as well as to testosterone. To investigate whether the exercise-induced changes in other steroid hormones were similar to that of testosterone, we measured serum levels of testosterone, androstenedione, dehydroepiandrosterone, and cortisol as well as gonadotropins, luteinizing hormone and follicle-stimulating hormone, and prolactin at 5–15 min intervals throughout progressive maximal intensity exercise on a cycle ergometer. Significant increases were observed with all hormones with exercise. The increase in serum testosterone began prior to exercise, peaked at 20 min after the beginning of exercise, and fell to baseline within 10 min. The serum luteinizing hormone increase was synchronous with that of testosterone, suggesting that gonadotropin stimulation was not responsible for the testosterone increment. The increments in serum cortisol, androstenedione, dehydroepiandrosterone, and prolactin levels were simultaneous but began 25–30 min after that of testosterone in all subjects. These findings, therefore, suggest that, contrary to previous evidence, the exercise-associated increase in serum testosterone results predominantly from a specific mechanism, presumably involving increased testicular production without gonadotropin stimulation.

To investigate if changes in circulating testosterone levels during isokinetic resistance exercise in women were similar to those during intense aerobic exercise and to examine concomitant changes in hemocon-centration, specific binding protein (sex hormone binding globulin-binding capacity), non-sex hormone binding globulin bound testosterone, luteinizing hormone, follicle-stimulating hormone, cortisol, and lactate, blood samples were obtained through an indwelling cannula at 30 and 15 min before exercise, after each of six exercises on upper and lower body muscle groups, and at 15 and 30 min after exercise in seven normal menstruating women. Investigations lasting approximately 60 min were performed in the early follicular phase beginning at 3.30 p.m. after two months of training with isokinetic (“Nautilus”) equipment. Baseline testosterone and non-sex hormone binding globulin bound testosterone levels were significantly higher in subjects than in a control group. Increased total and non-sex hormone binding globulin bound testosterone was observed immediately prior to exercise with further increases late in exercise, then with proportional increases in cortisol and lactic acid. Sex hormone binding globulin-binding capacity increased before exercise. The testosterone increments exceeded hemoconcentration. Luteinizing hormone and follicle-stimulating hormone levels increased during exercise. The data suggest that origins of the exercise-associated testosterone increment are complex, resulting from hemoconcentration and specific gonadal and adrenal responses.

Seventy-five infertile patients and twenty-five in whom displacement of an intrauterine device (IUD) had occurred were examined under general anesthesia. The Storz 4-mm hysteroscope was utilized. In all cases Hyskon, high-molecular weight dextran, was used as the distention medium. Concurrent laparoscopy was performed in 80 patients. The hysteroscopic findings were compared with preoperative salpingograms or pelvic x-radiographs.

Clinical and endocrine evaluations of 39 patients with hirsutism were performed to determine the effectiveness and site(s) of action of an antiandrogenic compound, spironolactone. Treatment with spironolactone at a dose of 200 mg/day resulted in a clear beneficial effect on the quantity and quality of facial hair growth in 19 of 20 patients with moderate to severe hirsutism. Regression of hirsutism in terms of diameter, density, and the rate of facial hair growth was noticeable within two months. The maximal effect was observed at six months and was maintained at 12 months of treatment. Spironolactone was equally effective in reducing hirsutism in women with polycystic ovary syndrome and idiopathic hirsutism. These clinical observations were associated with a prompt and sustained reduction in levels of androgen of ovarian origin without affecting levels of adrenal androgen and cortisol. Apart from diuresis, which was limited to the first few days of treatment, there were no discernible side effects during the one year of this study. Our results indicate that spironolactone is a highly effective and safe agent for the treatment of hirsutism through its inhibitory action on both ovarian androgen secretion and peripheral androgen action.(JAMA 1982;247:1295-1298)

Physical activity has a range of effects on male reproductive function depending upon the intensity and duration of the activity and the fitness of the individual. In general, it appears that relatively short, intense exercise increases serum testosterone levels, but there is debate to what degree haemoconcentration, decreased clearance and/or increased synthesis are involved. It is clear from the promptness of the testosterone increment that the mechanism does not involve gonadotrophin stimulation of the testes. There is suppression of serum testosterone levels during and subsequent to more prolonged exercise (and to some extent in the hours following intense short term exercise). Again the mechanisms are not clear: a variety of systems could influence the decrease of testosterone synthesis, including decreased gonadotrophin, increased cortisol, catecholamine or prolactin levels, or perhaps even an accumulation of metabolic waste materials. Endurance training induces changes in the function of the reproductive axis in men in a manner which appears similar to the changes in women. As in women, there is a subclinical inhibition of normal reproductive function but it is unclear whether clinical expression of reproductive suppression is common in men. The long term, physiological suppression of the hypothalamic-pituitary-gonadal axis in men is probably not of major significance but it is clear that further investigation in several areas is essential to provide continuing reassurance that ‘exercise is good for you’.

Endometrial biopsy specimens were obtained from 107 normally menstruating infertile women 2 to 3 days before the anticipated onset of menses and were day-dated according to histologic criteria. A simultaneous blood sample was obtained for measurement of progesterone (P) and beta-subunit of human chorionic gonadotropin. Of 98 biopsies which could be accurately dated, 56 were in-phase (IP) and 42 were out-of-phase (OOP). Mean serum P levels were significantly lower in women with OOP biopsies undertaken more than 4 days before the onset of menses. A sharp decline in serum P levels was observed in women with IP but not OOP biopsies, so that on the final premenstrual day serum P levels were significantly higher than normal in women with OOP biopsies. Pregnancy continued without interruption in two of six patients who underwent biopsy in the cycle of conception. One patient had an ectopic pregnancy; and the three remaining pregnant patients, all with subnormal P values, aborted. The study suggests that there is a high frequency of minor abnormalities in luteal function in normally menstruating, infertile women for whom tubal and male factors were normal. The frequency of subclinical pregnancy (2 of 107) was lower than anticipated from earlier studies.