Sign Reversal of Spin-Transfer Torques.

Spin-transfer torque (STT) and spin-orbit torque (SOT) form the core of spintronics, allowing for the control of magnetization through electric currents. While the sign of SOT can be manipulated through material and structural engineering, it is conventionally understood that STT lacks a degree of freedom in its sign. However, this study presents the first demonstration of manipulating the STT sign by engineering heavy metals adjacent to magnetic materials in magnetic heterostructures. Spin torques are quantified through magnetic domain-wall speed measurements, and subsequently, both STT and SOT are systematically extracted from these measurements. The results unequivocally show that the sign of STT can be either positive or negative, depending on the materials adjacent to the magnetic layers. Specifically, Pd/Co/Pd films exhibit positive STT, while Pt/Co/Pt films manifest negative STT. First-principle calculations further confirm that the sign reversal of STT originates from the sign reversal of spin polarization of conduction electrons.

Transfluthrin and Metofluthrin as Effective Repellents against Pyrethroid-Susceptible and Pyrethroid-Resistant Aedes aegypti (L.) (Diptera: Culicidae).

Aedes aegypti is a major vector of dengue fever in tropical regions. Spatial repellents (SRs) have shown promise in delaying pesticide resistance. Methods for discriminating concentrations (DCs) are well established using various bioassay tools, while data for high-throughput screening system (HITSS) toxicity bioassay (TOX) are absent. In this study, we compared and optimized lethal (LCs) and sub-lethal concentrations (SLCs) of transfluthrin (TFT) and metofluthrin (MFT) on pyrethroid-susceptible (USDA) and pyrethroid-resistant (Pu-Teuy) Ae. aegypti (L.) strains, using the HITSS-TOX. Mean mortality (MT) was 100% at LC99 and DC, compared to LC50 (45.0 ± 3.7%) and LC75 (65.8 ± 7.0%) for the USDA strain. However, the resistant strain (Pu-Teuy) showed reduced susceptibility against TFT and a significantly lower MT at LC50 (12.5 ± 4.4%; t = 5.665, df = 10, p < 0.001), LC75 (9.2 ± 3.5%; t = 4.844, df = 10, p = 0.001), LC99 (55.0 ± 9.9%; t = 4.538, df = 5, p = 0.006), and DC (75.0 ± 5.2%; U = 3.0, p = 0.007). The DC of TFT (0.15222%) was 4.7-fold higher than for MFT (0.03242%) in USDA strain. The baseline DCs established are useful to better understand susceptibility and the efficacy of various repellents against field populations of Ae. aegypti.

Multiple Walker breakdowns in magnetic multilayers.

Herein, we report an exotic domain-wall dynamics showing double Walker breakdowns in magnetic multilayer films composed of two magnetic layers. Such multiple Walker breakdowns are attributed to the internal magnetic dipole field, which is antisymmetric on the domain walls of the lower and upper magnetic layers. A micromagnetic simulation shows four phases of the domain-wall dynamics, which result in a phase diagram with the phase boundaries of the double Walker breakdown fields. Such double Walker breakdowns lead to two minima in the variation of the domain-wall velocity, as often observed experimentally.

Semi-field evaluation of novel chemical lures for Aedes aegypti, Culex quinquefasciatus, and Anopheles minimus (Diptera: Culicidae) in Thailand.

BACKGROUND: Entomological surveillance is an important means of assessing the efficacy of insect vector management programs and estimating disease transmission thresholds. Among baited traps, Biogents' BG-Sentinel (BGS) trap baited with BG-Lure is considered to have the most similar outcome to, and be a possible replacement for, human-landing catches for the epidemiologically relevant monitoring of adult Aedes aegypti and Culex quinquefasciatus. In contrast to the BGS trap, the Black Hole ultraviolet (UV) light trap, which is widely used to catch nocturnal flying insects, is not baited with synthetic human odor-mimicking lures. METHODS: We evaluated the L-lactic acid-based Kasetsart University (KU)-lures nos. 1-6 as novel candidate chemical lures for the diurnal species Ae. aegypti and the nocturnal species Cx. quinquefasciatus using two commercial traps (the BGS trap and the Black Hole UV light trap) in a semi-field screen (SFS) house. Firstly, we optimized the dose of each KU-lure in an SFS house (140 m3). Secondly, six different candidate KU-lures were screened by comparing their percent attraction using a single discriminating dose (0.5 g). Finally, we evaluated the synergism of the KU-lures selected in this way with commercially available traps. RESULTS: BGS traps baited with KU-lure no. 1 exhibited the greatest percent attraction for Ae. aegypti (29.5% ± 14.3%), whereas those baited with KU-lure no. 6 most strongly attracted Cx. quinquefasciatus (33.3% ± 10.7%). Interestingly, BGS traps treated with 10 g BG-Lure did not significantly attract more Ae. aegypti or Cx. quinquefasciatus than the untreated BGS traps. CO2 at a flow rate of 250 ml/min most strongly attracted both Ae. aegypti and Cx. quinquefasciatus (42.2% ± 14.2% and 75.1% ± 16.9%, respectively). BGS and Black Hole UV light traps with KU-lure no. 6 exhibited a stronger attraction for Cx. quinquefasciatus than untreated traps, and the percent attraction did not differ between the treated traps. CONCLUSIONS: Synergistic effects of KU-lures nos. 1 and 6 with the mosquito traps were demonstrated for both the diurnal and nocturnal species in the SFS house assays. However, further studies are urgently needed for the development of species-specific lures to increase trap efficacy in the field for local vector mosquitoes in Thailand.

Evaluation of Mosquito Attractant Candidates Using a High-Throughput Screening System for Aedes aegypti (L.), Culex quinquefasciatus Say. and Anopheles minimus Theobald (Diptera: Culicidae).

Several types of olfactometers have been used to evaluate mosquito responses to agents that mimic natural volatiles that repel or attract. The Y-tube olfactometer has been widely used to study repellents and attractants, while the high-throughput screening system assay has only been used to study repellents. Whether the high-throughput screening system assay is suitable for evaluating attractants is unknown. We evaluated the responses to four lactic-acid-based mixtures and two non-lactic-acid-based chemical lure candidates using the high-throughput screening system (HITSS) for three mosquito species (laboratory strains and field populations of both Aedes aegypti (L.) and Culex quinquefasciatus Say.; laboratory strain of Anopheles minimus Theobald) under laboratory-controlled conditions. HITSS assay results showed that KU-lure #1 elicited the greatest percent attraction for pyrethroid-resistant and -susceptible Ae. aegypti. KU-lure #6 elicited the strongest attractive response for pyrethroid-susceptible and -resistant Cx. quinquefasciatus and pyrethroid-susceptible An. minimus. The response to the lures from each species was independent of the pyrethroid susceptibility status (Ae. aegypti, p = 0.825; Cx. quinquefasciatus, p = 0.056). However, a significant difference in attraction to KU-lure #6 was observed between diurnal and nocturnal mosquitoes (Cx. quinquefasciatus vs. Ae. aegypti, p = 0.014; An. minimus vs. Ae. aegypti, p = 0.001). The laboratory-level HITSS assay effectively selects potential lure candidates. Because the host-seeking behavior differs between mosquito species, further studies are needed to develop species-specific attractants. Additional studies in semi-field screen houses using commercial traps are necessary to evaluate the accuracy of these laboratory assay results.

Dose-Response Assay for Synthetic Mosquito (Diptera: Culicidae) Attractant Using a High-Throughput Screening System.

Natural volatile host cues play a critical role for mosquito orientation and locating a blood source for egg production. Similar olfactory activation responses have allowed the use and development of artificial chemical attractants to lure mosquitoes to trapping devices. Using a pre-formulated commercial product mixture of different attractant chemicals, a high-throughput screening system (HITSS) is used to screen varying doses of chemical required to activate behavioral responses. Two strains of Aedes aegypti (L.): permethrin-susceptible (USDA) and -resistant (Pu Teuy) phenotypes and one Culex quinquefasciatus Say. (NIH) laboratory strain were tested. Overall, mosquitoes showed repellency between 1.0 g and to 10.0 g dose of each compound. However, by progressively reducing the dose, Cx. quinquefasciatus showed a greater positive percent attraction (88.9%) at 0.025 g, whereas the USDA and Pu Teuy Ae. aegypti produced optimum attractant activation at 0.005 g (72.6% and 58.9%, respectively) without significant difference within species (p > 0.05). In parallel control assays, Cx. quinquefasciatus was significantly attracted to 1 g of dry ice (carbon dioxide) (76%) more than Ae. aegypti (USDA) (12.2%). The HITSS was originally designed to measure three chemical actions to sublethal concentrations of chemicals by mosquitoes: toxicity and the two primary behavior avoidance responses (contact excitation and spatial repellency). These findings demonstrate that the HITSS assay, with only minor modifications, allows comparison screening of candidate compounds as potential attractants for anemotactic responses under laboratory-controlled conditions. Further investigations will be required to equate measurements obtained from controlled laboratory assays to more varied field conditions for attracting natural mosquito populations.

Performance of Commercial Insecticide Formulations Against Different Developmental Stages of Insecticide-Resistant Tropical Bed Bugs (Hemiptera: Cimicidae).

This study examined the presence of insecticide resistance in different developmental stages (adults, first instars, and eggs) of the tropical bed bug, Cimex hemipterus (F.) using several insecticide formulations. Adults and first instars of five strains (Queensland, Kuala Lumpur, Bukit Mertajam, Saujana, and Krystal Point) were evaluated using the surface contact method and compared with a susceptible strain (Monheim) of the common bed bug Cimex lectularius L. The insecticide formulations were used at their label rates in this study: Tandem (thiamethoxam [11.6%], lambda-cyhalothrin [3.5%]) at 183.96 mg/m2; Temprid SC (imidacloprid [21%], beta-cyfluthrin [10.5%]) at 106.13 mg/m2; Sumithion 20CS (fenitrothion [20%]) at 250 mg/m2; Pesguard FG161 (d-tetramethrin [4.4%], cyphenothrin [13.2%]) at 110 mg/m2; and Sumithrin 10SEC (d-phenothrin [10%]) at 100 mg/m2. Results showed a very high level of resistance to Pesguard FG161 (388.3 to >605.0 times) and Sumithrin (302.9 to >365.5 times) in all adults of the strains tested, whereas low to high levels of resistance were registered for Tandem (1.4-4.7 times), Temprid (7.3-16.7 times), and Sumithion (1.2-14.6 times) for adults of all bed bug strains. For first instars, resistance to the former two formulations were high to very high (31.4-118.1 times). In contrast, they showed lower resistance to Tandem, Temprid, and Sumithion (1.0-10.2 times). An immersion method used to test on bed bug eggs found high to very high resistance toward all tested formulations. Results demonstrate that the resistance level varies between bed bug developmental stages.

The effect of diabetes on 4-year changes of hearing thresholds in male workers exposed to noise in a single company: a longitudinal study.

BACKGROUND: Recently, several studies have assessed the association between diabetes and hearing impairment. However, the effect of diabetes on hearing impairment is not well known in diabetic patients exposed to noise, a typical cause of hearing impairment. The aim of this study is to longitudinally analyze the effect of diabetes on hearing impairment in workers exposed to similar noise levels from 2013 to 2017 who had experienced little change in their working conditions. METHODS: The study subjects included 2,087 male workers exposed to noise in a single company and who underwent health examinations at the same hospital in Ulsan city in 2013 and 2017. Hearing impairment was defined that a pure-tone average of pure-tone audiometry (PTA) thresholds at 1,000, 2,000, 3,000, and 4,000 Hz was 25 dB and over in both ears. Statistical analyses were conducted using χ2 tests, ANOVA, and Cox proportional hazard models. We analyzed covariates that might affect hearing impairment, including age; working period; levels of total cholesterol, triglyceride, and serum creatinine; smoking and alcohol history; and noise level. RESULTS: The average PTA thresholds and their average changes between 2013 and 2017 were significant in the diabetes mellitus (DM) group than those in the normal and impaired fasting glucose group. Among the subjects with the same status of fasting glucose group in 2013 and 2017, the adjusted hazard ratios for incident hearing impairment among those in the DM group compared to normal group were 3.35 (95% confidence interval [CI], 1.54-7.29) in the left ear and 5.66 (95% CI, 2.01-15.98) in the right ear. CONCLUSIONS: This study suggested that the risk of hearing impairment in the DM group was significantly higher than that in the normal group in both ears, even when exposed to similar noise levels.

Bulk Dzyaloshinskii-Moriya interaction in amorphous ferrimagnetic alloys.

Symmetry breaking is a fundamental concept that prevails in many branches of physics1-5. In magnetic materials, broken inversion symmetry induces the Dzyaloshinskii-Moriya interaction (DMI), which results in fascinating physical behaviours6-14 with the potential for application in future spintronic devices15-17. Here, we report the observation of a bulk DMI in GdFeCo amorphous ferrimagnets. The DMI is found to increase linearly with an increasing thickness of the ferrimagnetic layer, which is a clear signature of the bulk nature of DMI. We also found that the DMI is independent of the interface between the heavy metal and ferrimagnetic layer. This bulk DMI is attributed to an asymmetric distribution of the elemental content in the GdFeCo layer, with spatial inversion symmetry broken throughout the layer. We expect that our experimental identification of a bulk DMI will open up additional possibilities to exploit this interaction in a wide range of materials.

Application of cold intolerance symptom severity questionnaire among vibration-exposed workers as a screening tool for the early detection of hand-arm vibration syndrome: a cross-sectional study.

BACKGROUND: The detection rate of hand-arm vibration syndrome (HAVS) is very low in South Korea compared with other countries. The absence of uniform consensus and guidelines for diagnosing HAVS has been presumed to be one of the reasons. The HAVS has various manifestations including cold intolerance and its severity can be measured using the cold intolerance symptom severity (CISS) questionnaire. This study aimed to determine whether the CISS questionnaire, being used as a screening tool, can aid in the early detection of HAVS. METHODS: A total of 76 male workers with vibration-induced symptoms were enrolled as the final study participants. To compare the CISS score of healthy individuals, 41 men who had never been exposed to local vibration were included in the study. In addition to the former medical questionnaire, the participants answered the CISS questionnaire. A statistical analysis was conducted to identify the association of CISS scores with vibration induced symptom and to determine its cut off value. RESULTS: The reliability of the CISS questionnaire was proven to be good, with a total Cronbach's alpha of 0.922. The mean CISS score of the exposed group increased in every vascular stage [stage 0 = 42.6 (18.5); stage 1 = 59.4 (14.1); and over stage 2 = 60.2 (21.6)]. They were significantly higher than that of the non-exposed group. The result was fairly consistent with those in the sensorineural stage. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under curve (AUC) of 30 were 88.5, 65.3, 76.1, 82.1 and 0.769, respectively. From the result of logistic regression, the adjusted odds ratio of both components increased by the CISS score grouped by 30s. CONCLUSIONS: The self-reported CISS questionnaire, used to measure the degree of cold intolerance, showed high agreement with the Stockholm classification of HAVS. Hence, we recommend the use of this questionnaire to assess the level of cold intolerance among vibration-exposed workers and detect individuals who are at risk of vibration-induced impairment with a cutoff value of 30. TRIAL REGISTRATION: IRB No. 2018-07-040-001. Registered on 4 September 2018.

Vanishing skyrmion Hall effect at the angular momentum compensation temperature of a ferrimagnet.

In the presence of a magnetic field, the flow of charged particles in a conductor is deflected from the direction of the applied force, which gives rise to the ordinary Hall effect. Analogously, moving skyrmions with non-zero topological charges and finite fictitious magnetic fields exhibit the skyrmion Hall effect, which is detrimental for applications such as skyrmion racetrack memory. It was predicted that the skyrmion Hall effect vanishes for antiferromagnetic skyrmions because their fictitious magnetic field, proportional to net spin density, is zero. Here we investigate the current-driven transverse elongation of pinned ferrimagnetic bubbles. We estimate the skyrmion Hall effect from the angle between the current and the bubble elongation directions. The angle and, hence, the skyrmion Hall effect vanishes at the angular momentum compensation temperature where the net spin density vanishes. Furthermore, our study establishes a direct connection between the fictitious magnetic field and the spin density.

Optimal angle of magnetic field for magnetic bubblecade motion.

Unidirectional motion of magnetic structures such as the magnetic domain and domain walls is a key concept underlying next-generation memory and logic devices. As a potential candidate of such unidirectional motion, it has been recently demonstrated that the magnetic bubblecade-the coherent unidirectional motion of magnetic bubbles-can be generated by applying an alternating magnetic field. Here we report the optimal configuration of applied magnetic field for the magnetic bubblecade. The tilted alternating magnetic field induces asymmetric expansion and shrinkage of the magnetic bubbles under the influence of the Dzyaloshinskii-Moriya interaction, resulting in continuous shift of the bubbles in time. By examining the magnetic bubblecade in Pt/Co/Pt films, we find that the bubblecade speed is sensitive to the tilt angle with a maximum at an angle, which can be explained well by a simple analytical form within the context of the domain-wall creep theory. A simplified analytic formula for the angle for maximum speed is then given as a function of the amplitude of the alternating magnetic field. The present results provide a useful guideline of optimal design for magnetic bubblecade memory and logic devices.

Wide-Range Probing of Dzyaloshinskii-Moriya Interaction.

The Dzyaloshinskii-Moriya interaction (DMI) in magnetic objects is of enormous interest, because it generates built-in chirality of magnetic domain walls (DWs) and topologically protected skyrmions, leading to efficient motion driven by spin-orbit torques. Because of its importance for both potential applications and fundamental research, many experimental efforts have been devoted to DMI investigation. However, current experimental probing techniques cover only limited ranges of the DMI strength and have specific sample requirements. Thus, there are no versatile methods to quantify DMI over a wide range of values. Here, we present such an experimental scheme, which is based on the angular dependence of asymmetric DW motion. This method can be used to determine values of DMI much larger than the maximum strength of the external magnetic field strength, which demonstrates that various DMI strengths can be quantified with a single measurement setup. This scheme may thus prove essential to DMI-related emerging fields in nanotechnology.

Differences in Climbing Ability of Cimex lectularius and Cimex hemipterus (Hemiptera: Cimicidae).

The climbing abilities of two bed bug species, Cimex lectularius L. and Cimex hemipterus (F.), were determined by evaluating their escape rates from smooth surface pitfall traps using four commercial bed bug monitors (Verifi Bed Bug Detector, ClimbUp Insect Interceptor, BlackOut Bed Bug Detector, and SenSci Volcano Bed Bug Detector). All detectors were used in the absence of lures or attractants. Unlike C. lectularius, adult C. hemipterus were able to escape from all traps. On the other hand, no or a low number nymphs of both species escaped, depending on the evaluated traps. Examination of the vertical friction force of adults of both species revealed a higher vertical friction force in C. hemipterus than in C. lectularius. Scanning electron microscope micrograph observation on the tibial pad of adult bed bugs of C. hemipterus showed the presence of a greater number of tenent hairs on the tibial pad than on that of adult C. lectularius. No tibial pad was found on the fourth and fifth instars of both species. Near the base of the hollow tenent hairs is a glandular epithelium that is better developed in adult C. hemipterus than in adult C. lectularius. This study highlights significant morphological differences between C. lectularius and C. hemipterus, which may have implications in the monitoring and management of bed bug infestations.

Cylindrical Water Triboelectric Nanogenerator via Controlling Geometrical Shape of Anodized Aluminum for Enhanced Electrostatic Induction.

We demonstrate a cylindrical water triboelectric nanogenerator (CW-TENG) that generates sustainable electrical output. The inner surface of the cylinder was patterned into superhydrophobic and hydrophilic parts to control water flow inside the packaged design of CW-TENG. Here, various thicknesses and roughnesses of the superhydrophobic surface, generated using aluminum oxide nanostructures for enhanced electrostatic induction, were measured to obtain the maximum output and superhydrophobicity. Also, we demonstrate the possibility of using a hydrophilic surface for energy harvesting and as a water reservoir in the packaged design.

Impact of diabetes on treatment outcomes and long-term survival in multidrug-resistant tuberculosis.

BACKGROUND: Few studies have investigated the impact of diabetes mellitus (DM), a globally increasing metabolic disease, on treatment outcomes and long-term survival in patients with multidrug-resistant forms of tuberculosis (MDR-TB). OBJECTIVES: We analyzed outcomes in a large cohort to assess the impact of DM on treatment outcomes of patients with MDR-TB. METHODS: MDR-TB patients newly diagnosed or retreated between 2000 and 2002 and followed for 8-11 years were retrospectively analyzed with respect to the effect of DM as a comorbidity on their treatment outcome and long-term survival. RESULTS: Of 1,407 patients with MDR-TB, 239 (17.0%) had coexisting DM. The mean age and body mass index were higher in MDR-TB patients with DM [MDR-TBDM(+)] than in those without DM [MDR-TBDM(-)]. Patients with MDR-TB and a comorbidity of DM had a significantly lower treatment success rate than those without a history of DM (36.0 vs. 47.2%, p = 0.002). In addition, DM was the negative predictor for MDR-TB treatment success in multivariate analyses [odds ratio 0.51, 95% confidence interval (CI) 0.26-0.99]. Mean survival times were also lower in MDR-TBDM(+) than in MDR-TBDM(-) patients (102 vs. 114 months, p = 0.001), with DM as a significant predictor of poor long-term survival in multivariate analyses (hazard ratio 1.59, 95% CI 1.01-2.50). CONCLUSIONS: Among MDR-TB patients, DM was a relatively common comorbidity. In patients undergoing treatment for MDR-TB and followed for 8-11 years, it was found to be independently associated with an increased risk of both treatment failure and death.

Treatment outcome and mortality among patients with multidrug-resistant tuberculosis in tuberculosis hospitals of the public sector.

This study was conducted to evaluate treatment outcome, mortality, and predictors of both in patients with multidrug-resistant tuberculosis (MDR-TB) at 3 TB referral hospitals in the public sector of Korea. We included MDR-TB patients treated at 3 TB referral hospitals in 2004 and reviewed retrospectively their medical records and mortality data. Of 202 MDR-TB patients, 75 (37.1%) had treatment success and 127 (62.9%) poor outcomes. Default rate was high (37.1%, 75/202), comprising 59.1% of poor outcomes. Male sex (adjusted odds ratio [aOR], 2.91; 95% confidence interval [CI], 1.13-7.49), positive smear at treatment initiation (aOR, 5.50; 95% CI, 1.22-24.90), and extensively drug-resistant TB (aOR, 10.72; 95% CI, 1.23-93.64) were independent predictors of poor outcome. The all-cause mortality rate was 31.2% (63/202) during the 3-4 yr after treatment initiation. In conclusion, the treatment outcomes of patients with MDR-TB at the 3 TB hospitals are poor, which may reflect the current status of MDR-TB in the public sector of Korea. A more comprehensive program against MDR-TB needs to be integrated into the National Tuberculosis Program of Korea.

Fetal pyelectasis as predictor of decreased differential renal function.

PURPOSE: A decreased percent of differential function is a common indication for infant pyeloplasty but there is no recognized fetal ultrasound parameter to predict this deficit. We determined whether there is a correlation between fetal pyelectasis and the newborn percent differential function that may enhance prenatal counseling and guide postnatal evaluation. MATERIALS AND METHODS: Our database was queried for fetal and newborn measures with fetal pyelectasis on ultrasound and the percent of differential function on renal scintigraphy. Fetal pyelectasis data were stratified by estimated gestational age and the percent of differential function. The affected cohort was defined as having 35% or less differential function and the unaffected cohort was defined as having greater than 35%. The Wilcoxon 2-sample test was used for statistical analysis with logistic regression to generate estimated probability models of a decreased percent of differential function vs mm fetal pyelectasis. RESULTS: A total of 831 cases had fetal and newborn ultrasound data available with a total of 229 renal scans identified. Of the 229 cases 36 (16%) had 35% or less differential function on scintigraphy. At estimated gestational age 33 weeks or less the affected cohort had 8 mm greater pyelectasis than the unaffected cohort (OR 1.2, p <0.0001). At estimated gestational age greater than 33 weeks the affected cohort had 4 mm greater pyelectasis than the unaffected cohort (OR 1.07, p <0.07). Subgroup analysis before 33 weeks of estimated gestational age showed similar significance (OR >1, p

Outcomes of radical prostatectomy for patients with clinical stage T1a and T1b disease.

OBJECTIVE: To compare the outcomes between patients with stage T1a/b with those of patients with T1c cancer of the prostate treated with radical retropubic prostatectomy (RRP), as the appropriate management of clinical stage T1a/b prostate cancer is subject to debate; although many patients are managed expectantly, some have adverse pathological features suggesting that more active treatment might be beneficial. PATIENTS AND METHODS: From 1983 to 2003, 3478 men had RRP by one surgeon. From this group, we retrospectively identified 29 men with clinical stage T1a and 83 with clinical stage T1b disease. Using statistical analysis we compared the treatment outcomes of these patients with those of 1774 men with clinical stage T1c disease. RESULTS: Men with T1a/b disease had a significantly lower preoperative prostate-specific antigen (PSA) level, a greater proportion with organ-confined disease, and a lower mean/median prostatectomy Gleason score than those with T1c disease. Also, men with T1a/b disease were less likely to be potent before surgery, although the frequency of recovery of potency was similar among all groups. On multivariate analysis with age, year of surgery, PSA level and Gleason score, there was no statistical difference in the rates of biochemical recurrence and the 10-year overall survival rates. However, patients with T1b disease had a significantly lower cancer-specific survival. CONCLUSIONS: T1a and T1b prostate cancer can be associated with aggressive pathological features and have a similar rate of progression as clinical stage T1c disease. That notwithstanding, most patients in the study were cured with RRP and had favourable long-term functional outcomes.

Water-soluble carbon nanotube-enzyme conjugates as functional biocatalytic formulations.

We report the activity, stability, and reusability of enzyme-carbon nanotube conjugates in aqueous solutions. A variety of enzymes were covalently attached to oxidized multi-walled carbon nanotubes (MWNTs). These conjugates were soluble in aqueous buffer, retained a high fraction of their native activity, and were stable at higher temperatures relative to their solution phase counterparts. Furthermore, the high surface area of MWNTs afforded high enzyme loadings, yet the intrinsic high length of the MWNT led to facile filtration. These water-soluble carbon nanotube-enzyme conjugates represent novel preparations that possess the virtues of both soluble and immobilized enzymes, thus providing a unique combination of useful attributes such as low mass transfer resistance, high activity and stability, and reusability.