Demonstrating Agreement between Radio and Fluorescence Measurements of the Depth of Maximum of Extensive Air Showers at the Pierre Auger Observatory

We show, for the first time, radio measurements of the depth of shower maximum (X_{max}) of air showers induced by cosmic rays that are compared to measurements of the established fluorescence method at the same location. Using measurements at the Pierre Auger Observatory we show full compatibility between our radio and the previously published fluorescence dataset, and between a subset of air showers observed simultaneously with both radio and fluorescence techniques, a measurement setup unique to the Pierre Auger Observatory. Furthermore, we show radio X_{max} resolution as a function of energy and demonstrate the ability to make competitive high-resolution X_{max} measurements with even a sparse radio array. With this, we show that the radio technique is capable of cosmic-ray mass composition studies, both at Auger and at other experiments.

Cardiac output monitoring using transthoracic echocardiography in children after cardiac surgery-an observational study of feasibility and concordance with transpulmonary thermodilution

Background

Transthoracic echocardiography (TTE) is commonly used after pediatric cardiac surgery to monitor cardiac function and adequacy of surgery; however it depends on the availability of good echo window and operator skill [1]. Transpulmonary thermodilution (TPTD) is feasible along with calibrated continuous cardiac output measurement in children but seldom used due to cost and the need for a specialized catheter [2].

We hypothesized that TTE would be as good as TPTD, but limited in feasibility following pediatric cardiac surgery. Hence, the concordance, agreement as well as feasibility and trending of cardiac output monitoring by TTE was compared against a reference TPTD method in real-world usage in children after congenital heart surgery.

Methods

This was a secondary analysis of data from a previously registered and conducted study in our unit. TPTD monitoring was instituted in children undergoing congenital heart disease repair on cardiopulmonary bypass with a 3F femoral arterial cannula and a central venous injectate temperature sensor.

Cardiac output was also measured by transthoracic echocardiography by measurement of the left ventricular outflow tract (LVOT) diameter, LVOT velocity time integral (VTI) and the heart rate as previously described [3,4]. Measurements were taken after arrival in the ICU, and every 12 hours till after extubation. Correlation, Bland-Altman analysis and polar analysis was done for cardiac output measured by TPTD and TTE.

Results

TTE and TPTD measurements of cardiac output correlated well (Pearson's correlation coefficient 0.94; 95% CI 0.90–0.96) (Fig. 1A). Bland Altman analysis showed a mean bias of 0.15 l/min and upper and lower limits of agreement of 0.81 and −0.51 l/min respectively (Fig. 1B). Cardiac output measurement by TTE was possible in 72 instances while TPTD allowed measurement in all 113 instances. Hence, TTE was not feasible in 41 instances across 14 patients, including 19 instances in acyanotic and 22 instances in cyanotic patients. Polar analysis revealed acceptable trending.

Conclusions

TTE derived cardiac output demonstrated good correlation, minimal bias and narrow limits of agreement versus TPTD, and was feasible in most cases. This suggests TTE is an acceptable cardiac output measurement modality post pediatric cardiac surgery, as in adults [5]. TPTD-based continuous cardiac output monitoring might have a complementary role in pediatric cardiac critical care, particularly in high risk cases.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Institutional Special Research Grant from Postgraduate Institute of Medical Education and Research, Chandigarh, India. Figure 1

Prices of combination medicines and single-molecule antihypertensive medicines in India's private health care sector

More than half of patients with hypertension require two or more medicines to control blood pressure. Combinations of anti‐hypertensive medicines are available as Single Pill Combinations (SPCs) or Single Agent Pills (SAPs). SPCs of two or more anti‐hypertensive medicines facilitate simpler dosing schedules, decrease pill burden, increase adherence to medicine, and simplify procurement and distribution. Despite this, equivalent combinations of separate pills (SAPs) are often prescribed instead of SPCs under the assumption that SAPs are priced lower. This study compared prices of anti‐hypertensive SPCs and equivalent SAPs in the private health care sector of India. High sales volume anti‐hypertensive SPCs and SAPs were selected from 2018 private sector pharmaceutical sales data. SPCs and SAPs price information was collected from online pharmacy websites between November 2019 and January 2020. Anti‐hypertensive SPCs represent approximately 39.1% of India's private sector anti‐hypertensive drug market. Multiple manufacturers produce the same top‐selling SPCs, suggesting a viable and competitive market. A comparison of SPCs and SAPs across different manufacturers showed that the lowest prices of both SPCs and the sum of component SAPs were nearly identical across different manufacturers. An analysis of dual‐drug SPCs and SAPs by the same manufacturer showed that most manufacturers (five of six) had priced their SPCs higher than SAPs. These observations suggest that the price of SPCs could be lowered to match the combined price of the component SAPs, and manufacturing costs and market forces do not present a barrier to the implementation of anti‐hypertensive SPCs.

Fine-tuning the photosynthetic light harvesting apparatus for improved photosynthetic efficiency and biomass yield

Photosynthetic electron transport rates in higher plants and green algae are light-saturated at approximately one quarter of full sunlight intensity. This is due to the large optical cross section of plant light harvesting antenna complexes which capture photons at a rate nearly 10-fold faster than the rate-limiting step in electron transport. As a result, 75% of the light captured at full sunlight intensities is reradiated as heat or fluorescence. Previously, it has been demonstrated that reductions in the optical cross-section of the light-harvesting antenna can lead to substantial improvements in algal photosynthetic rates and biomass yield. By surveying a range of light harvesting antenna sizes achieved by reduction in chlorophyll b levels, we have determined that there is an optimal light-harvesting antenna size that results in the greatest whole plant photosynthetic performance. We also uncover a sharp transition point where further reductions or increases in antenna size reduce photosynthetic efficiency, tolerance to light stress, and impact thylakoid membrane architecture. Plants with optimized antenna sizes are shown to perform well not only in controlled greenhouse conditions, but also in the field achieving a 40% increase in biomass yield.

Redefining public health leadership in the sustainable development goal era

Adoption of the Sustainable Development Goals (SDGs) by member states of the United Nations (UN) has set a new agenda for public health action at national and global levels. The changed context calls for a reframing of what constitutes effective leadership in public health, through a construct that reflects the interdependence of leadership at multiple levels across the health system and its partners in other sectors. This is especially important in the context of Low and Middle Income Countries (LMICs) that are facing complex demographic and epidemiological transitions. The health system needs to exercise leadership that effectively mobilises all its resources for maximising health impact, and channels trans-disciplinary learning into well-coordinated multi-sectoral action on the wider determinants of health. Leadership is essential not only at the level of inspirational individuals who can create collective vision and commitment but also at the level of supportive institutions situated in or aligned to the health system. In turn, the health system as a whole has to exercise leadership that advances public health in the framework of sustainable development. This commentary examines the desirable attributes of effective leadership at each of these levels and explores the nature of their inter-dependence.

Reusable High Aspect Ratio 3-D Nickel Shadow Mask

Shadow Mask technology has been used over the years for resistless patterning and to pattern on unconventional surfaces, fragile substrate and biomaterial. In this work, we are presenting a novel method to fabricate high aspect ratio (15:1) three-dimensional (3D) Nickel (Ni) shadow mask with vertical pattern length and width of 1.2 mm and 40 μm respectively. The Ni shadow mask is 1.5 mm tall and 100 μm wide at the base. The aspect ratio of the shadow mask is 15. Ni shadow mask is mechanically robust and hence easy to handle. It is also reusable and used to pattern the sidewalls of unconventional and complex 3D geometries such as microneedles or neural electrodes (such as the Utah array). The standard Utah array has 100 active sites at the tip of the shaft. Using the proposed high aspect ratio Ni shadow mask, the Utah array can accommodate 300 active sites, 200 of which will be along and around the shaft. The robust Ni shadow mask is fabricated using laser patterning and electroplating techniques. The use of Ni 3D shadow mask will lower the fabrication cost, complexity and time for patterning out-of-plane structures.

Different methods to alter surface morphology of high aspect ratio structures

In various applications such as neural prostheses or solar cells, there is a need to alter the surface morphology of high aspect ratio structures so that the real surface area is greater than geometrical area. The change in surface morphology enhances the devices functionality. One of the applications of altering the surface morphology is of neural implants such as the Utah electrode array (UEA) that communicate with single neurons by charge injection induced stimulation or by recording electrical neural signals. For high selectivity between single cells of the nervous system, the electrode surface area is required to be as small as possible, while the impedance is required to be as low as possible for good signal to noise ratios (SNR) during neural recording. For stimulation, high charge injection and charge transfer capacities of the electrodes are required, which increase with the electrode surface. Traditionally, researchers have worked with either increasing the roughness of the existing metallization (Platinum grey, black) or other materials such as Iridium Oxide and PEDOT. All of these previously investigated methods lead to more complicated metal deposition processes that are difficult to control and often have a critical impact on the mechanical properties of the metal films. Therefore, a modification of the surface underneath the electrode's coating will increase its surface area while maintaining the standard and well controlled metal deposition process. In this work, the surfaces of the Silicon micro-needles were engineered by creating a defined microstructure on the electrodes surface using several methods such as Laser ablation, focused ion beam, sputter etching, reactive ion etching (RIE) and deep reactive ion etching (DRIE). The surface modification processes were optimized for the high aspect ratio Silicon structures of the UEA. The increase in real surface area while maintaining the geometrical surface area was verified using scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The best results were obtained by DRIE induced surface morphology. Decreases in impedance values of electrodes up to 76 % indicate the successful surface engineering of the high aspect ratio Silicon structures.

Pain relief after Frey's procedure for chronic pancreatitis

BACKGROUND

Few studies have addressed long-term pain relief after Frey's procedure (local head resection with lateral pancreaticojejunostomy, LR-LPJ) for chronic pancreatitis. This retrospective study evaluated pain control using a validated score and risk factors associated with failure to achieve complete pain relief following LR-LPJ.

METHODS

Sixty of 134 patients with chronic pancreatitis underwent LR-LPJ and were evaluated prospectively using the Izbicki pain score before surgery, and 1, 2, 5 and 7 years later. Analysis was on an intention-to-treat basis and predictors of complete pain relief were identified by multivariable analysis.

RESULTS

After a median follow-up of 6.4 years, the median pain score was reduced from 46.4 to 10.0 (P < 0.001) with partial or complete pain relief in 75 per cent of patients, and a significant reduction in median number of episodes requiring hospitalization (from 4 to 0; P < 0.001). Preoperative use of opiate medication (odds ratio (OR) 30.14; P = 0.015), continuous pattern of pain (OR 22.65; P = 0.025) and occurrence of postoperative complications (OR 10.52; P = 0.030) were significant predictors of failure to achieve complete pain relief after surgery.

CONCLUSION

Frey's procedure leads to significant and sustained long-term pain relief in patients with chronic pancreatitis. Patients should be referred for surgery before opiates are needed to relieve pain.

A Wafer-Scale Etching Technique for High Aspect Ratio Implantable MEMS Structures

Microsystem technology is well suited to batch fabricate microelectrode arrays, such as the Utah electrode array (UEA), intended for recording and stimulating neural tissue. Fabrication of the UEA is primarily based on the use of dicing and wet etching to achieve high aspect ratio (15:1) penetrating electrodes. An important step in the array fabrication is the etching of electrodes to produce needle-shape electrodes with sharp tips. Traditional etching processes are performed on a single array, and the etching conditions are not optimized. As a result, the process leads to variable geometries of electrodes within an array. Furthermore, the process is not only time consuming but also labor-intensive. This report presents a wafer-scale etching method for the UEA. The method offers several advantages, such as substantial reduction in the processing time, higher throughput and lower cost. More importantly, the method increases the geometrical uniformity from electrode to electrode within an array (1.5 ± 0.5 % non-uniformity), and from array to array within a wafer (2 ± 0.3 % non-uniformity). Also, the etching rate of silicon columns, produced by dicing, are studied as a function of temperature, etching time and stirring rate in a nitric acid rich HF-HNO(3) solution. These parameters were found to be related to the etching rates over the ranges studied and more-importantly affect the uniformity of the etched silicon columns. An optimum etching condition was established to achieve uniform shape electrode arrays on wafer-scale.

Integrated wireless neural interface based on the Utah electrode array

This report presents results from research towards a fully integrated, wireless neural interface consisting of a 100-channel microelectrode array, a custom-designed signal processing and telemetry IC, an inductive power receiving coil, and SMD capacitors. An integration concept for such a device was developed, and the materials and methods used to implement this concept were investigated. We developed a multi-level hybrid assembly process that used the Utah Electrode Array (UEA) as a circuit board. The signal processing IC was flip-chip bonded to the UEA using Au/Sn reflow soldering, and included amplifiers for up to 100 channels, signal processing units, an RF transmitter, and a power receiving and clock recovery module. An under bump metallization (UBM) using potentially biocompatible materials was developed and optimized, which consisted of a sputter deposited Ti/Pt/Au thin film stack with layer thicknesses of 50/150/150 nm, respectively. After flip-chip bonding, an underfiller was applied between the IC and the UEA to improve mechanical stability and prevent fluid ingress in in vivo conditions. A planar power receiving coil fabricated by patterning electroplated gold films on polyimide substrates was connected to the IC by using a custom metallized ceramic spacer and SnCu reflow soldering. The SnCu soldering was also used to assemble SMD capacitors on the UEA. The mechanical properties and stability of the optimized interconnections between the UEA and the IC and SMD components were measured. Measurements included the tape tests to evaluate UBM adhesion, shear testing between the Au/Sn solder bumps and the substrate, and accelerated lifetime testing of the long-term stability for the underfiller material coated with a a-SiC(x):H by PECVD, which was intended as a device encapsulation layer. The materials and processes used to generate the integrated neural interface device were found to yield a robust and reliable integrated package.

A Novel Method of Fabricating Convoluted Shaped Electrode Arrays for Neural and Retinal Prostheses

A novel fabrication technique has been developed for creating high density (6.25 electrodes/mm(2)), out of plane, high aspect ratio silicon-based convoluted microelectrode arrays for neural and retinal prostheses. The convoluted shape of the surface defined by the tips of the electrodes could compliment the curved surfaces of peripheral nerves and the cortex, and in the case of retina, its spherical geometry. The geometry of these electrode arrays has the potential to facilitate implantation in the nerve fascicles and to physically stabilize it against displacement after insertion. This report presents a unique combination of variable depth dicing and wet isotropic etching for the fabrication of a variety of convoluted neural array geometries. Also, a method of deinsulating the electrode tips using photoresist as a mask and the limitations of this technique on uniformity are discussed.

First Report of Plum pox virus on Plum in New York State

Plum pox, also known as Sharka, is one of the more significant viral diseases of stone fruit trees such as plum, peach, and apricot. It was first reported in Europe in the early 1900s and more recently in Chile in 1992, the United States (Pennsylvania) in 1999, Canada (Ontario and Nova Scotia) in 2000, China in 2001, and Argentina in 2004. Plum pox virus (PPV) was recently detected in two plum (Prunus domestica) trees in an orchard in Niagara County, NY, located within 5 miles from a Canadian plum pox eradication zone. Typical symptoms of chlorotic rings and spots were observed on some of the leaves from these trees. No symptoms were reported prior to the survey collection in July 2006. Survey samples were screened for the presence of PPV by ELISA using the Agdia PPV (Agdia, Elkhart, IN) specific kit that recognizes all strains but C of PPV. Approximately 5% of the survey samples were additionally analyzed by a validated immunocapture reverse transcription (IC-RT)-PCR TaqMan assay in a Cepheid SmartCycler (Cepheid, Sunnyvale, CA). Both replicates of the two New York plum trees produced a positive ELISA reaction in two consecutive tests. The ELISA-positive samples also produced positive results when subjected to the real-time IC-RT-PCR test. The PPV-positive trees were sampled again and an additional 53 samples were collected from trees in the surrounding area. Suspect trees again tested positive, while all the trees in the surrounding area tested negative. The methods used for confirmation included two ELISA tests (Durviz [Valencia, Spain] DAS indirect monoclonal ELISA and Agdia DAS polyclonal ELISA). Confirmatory real-time IC-RT-PCR was performed using universal 3' nontranslated region (NTR) primers (2,3) in a SYBR Green assay format and a coat protein (CP) primers/probe TaqMan assay (3,4). Further, the New York PPV isolate was identified as PPV D group using a subgroup specific conventional IC-RT-PCR (1). A 1.4-kb sequence fragment from the 3' end of the New York PPV was sequenced (GenBank Accession No. DG 883816). Comparison of the sequence with the database confirmed this isolate as subgroup D and exhibited a high degree of identity with other PPV D accessions (PPV D Teycheney [Accession No. X16415]; Penn4 [Accession No. DQ465243] Cnd 123-1 [Accession No. AY9553267]; and Cnd 3 [Accession No. AY953262]). To our knowledge, this is the first report of PPV in New York. References: (1) T. Candresse et al. Phytopathology. 88:198, 1998. (2) L. Levy et al. J. Virol. Methods. 49:295, 1994. (3) V. Mavrodieva and L. Levy. Acta Hortic. 657:141, 2004. (4) T. Wetzel et al. J.Virol. Methods 33:355, 1991.

Direct maxacalcitol injection into hyperplastic parathyroids improves skeletal changes in secondary hyperparathyroidism

Direct maxacalcitol (OCT) injection into a parathyroid gland (PTG) ameliorates several important etiologic factors of resistance to medical treatments for secondary hyperparathyroidism (s-HPT): the upregulations of vitamin D receptor (VDR) and Ca-sensing receptor (CaSR) in PTGs and the regression of PTG hyperplasia by the induction of apoptosis. In this study, we evaluated the bone histomorphology on the basis of maintaining these effects in advanced s-HPT. Five/six nephrectomized Sprague-Dawley rats were fed a high-phosphorus and low-calcium diet for 8 weeks. These rats were divided into four treatment groups: (1) basic uremic (at the baseline), (2) direct OCT single injection into PTGs (DI-OCT) followed by OCT intravenous administration for 4 weeks (IV-OCT), (3) direct vehicle injection and IV-OCT, and (4) no treatment for an additional 4 weeks. The effects of these treatments on serum intact-parathyroid hormone (PTH) level, PTG weight, VDR and CaSR expression levels in PTGs, and bone histomorphometric parameters were investigated. In the DI-OCT+IV-OCT group, the significant decrease in serum intact-PTH level was maintained by the following IV-OCT. A significant decrease in PTG weight and the upregulations of VDR and CaSR expression levels in PTGs were also observed. Bone histomorphometric analysis showed significant improvements in osteitis fibrosa in both cancellous and cortical bones. However, these findings were not observed in the other groups. These results suggest that osteitis fibrosa caused by advanced s-HPT can be successfully reversed by a control of PTH at an appropriate level through the improvement of PTG hyperplasia as induced by DI-OCT+IV-OCT.

Direct injection of calcitriol or its analog into hyperplastic parathyroid glands induces apoptosis of parathyroid cells

Hyperplasia of the parathyroid gland (PTG) is associated not only with excessive secretion of parathyroid hormone (PTH) but also with changes in the parathyroid cell (PTC) characteristics (i.e. hyperproliferative activity, and low contents of vitamin D and calcium-sensing receptors). Control of PTG hyperplasia is most important in the management of secondary hyperparathyroidism, but the advanced stage of hyperplasia is considered irreversible. In the present study, dialysis patients with PTG hyperplasia underwent direct injection of calcitriol or maxacalcitol (OCT) into the PTG. Ultrasonography showed that this treatment had significantly reduced PTG volume and tissue analysis using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) method and DNA electrophoresis indicated that cellular apoptosis had been induced. The mechanism of apoptosis was evaluated in detail in uremic rats fed a high-phosphate diet. OCT or its vehicle was directly injected into the rats' PTGs. In the PTGs treated by OCT, there was a significantly increased number of TUNEL-positive PTCs and DNA electrophoresis revealed the characteristic ladder pattern of DNA fragmentation, both findings indicative of apoptosis. There was also a significant upregulation of both vitamin D and Ca-sensing receptors in the PTCs and a clear shift of the Ca-PTH response curve to the left and downward. None of these findings was observed in the PTGs treated by vehicle. This novel treatment is successful in causing regression of PTG hyperplasia. Thus, it is expected to significantly reduce the PTH level and ameliorate the abnormal bone turnover and mineral metabolism.

Risk factors for perforation in microbial corneal ulcers in north India

AIM

To identify predisposing factors leading to corneal perforation in patients with microbial keratitis.

METHOD

Two groups of 60 patients each, with perforated corneal ulcers and healed/healing corneal ulcers, respectively, were recruited in a case-control study conducted in northern India. The cases and controls were matched by age and time of presentation. A standardised proforma was used to identify potential predisposing factors for demographic, social, medical, ocular, and treatment history. All participants underwent a detailed ocular examination. Corneal scrapings were performed where relevant.

RESULTS

The characteristics associated with corneal perforation in microbial keratitis were outdoor occupation (p = 0.005), illiteracy (p = 0.02), excessive alcohol use (p = 0.03), history of "something falling into eye" (p = 0.003), trauma with vegetable matter (p = 0.008), vision less than counting fingers at referral (p<0.001), central location of ulcer (p<0.001), lack of corneal vascularisation (p<0.001), delay in starting initial treatment (p<0.001), failure to start fortified antibiotics (p<0.001), and monotherapy with fluoroquinolones (p = 0.002). The lack of corneal vascularisation (OR 6.4, 95% CI 4.2 to 13.5), delay in starting initial treatment (OR 35.6, 95% CI 6.9 to 68.2), and failure to start fortified antibiotics (OR 19.9, 95% CI 2.7 to 64.7) retained significance on a logistic regression model.

CONCLUSIONS

This study characterises microbial keratitis cases at increased risk of corneal perforation and reinforces the need for standardised referral and treatment protocols for patients with corneal ulcer on their first contact at primary care level in the developing world.

Role of early trabeculectomy in primary open-angle glaucoma in the developing world

BACKGROUND

The lack of prospective data comparing early surgery and medical management in primary open-angle glaucoma (POAG) in the developing world led us to conduct a small randomised controlled clinical trial to evaluate acceptance and effectiveness of early trabeculectomy in these patients.

METHODS

A total of 60 patients with moderately advanced POAG were randomised into three groups (Group I-Conventional medical management, Group II-Option for early trabeculectomy, Group III-Received an educational package about their disease before an option for early trabeculectomy). The patients were followed up for a period of 6 months for visual acuity, intraocular pressures (IOP), and subjective satisfaction.

RESULTS

The three study groups were statistically similar with respect to mean IOP, demographic, and socio-economic profile. 35% of the patients accepted early surgery when offered a choice between early surgery and medical management in one of the groups. 65% of patients in another group expressed willingness for an early surgery after receiving health education on glaucoma. The mean IOP in the operated eyes was lower than the medically treated eyes at 2 weeks (16.6 vs 23.0 mmHg), 6 months (18.5 vs 22.8 mmHg), and 1-year review (17.9 vs 22.3 mmHg) (P<0.001). No significant difference was seen among the groups with regard to visual acuity and subjective satisfaction.

CONCLUSION

There is a reasonable acceptance of early surgery in POAG patients in the developing world and increases on educating patients about their disease. Early surgery offers better IOP control with no long-term subjective adverse effects.

Biliary complications of pancreatic necrosis

BACKGROUND

Involvement of the biliary tract in pancreatic necrosis is rare. The authors are presenting six patients with this unusual complication.

METHODS

Retrospective analysis of a case series.

RESULTS

The necrotic process involved the bile duct in four patients (bile duct alone in two and bile duct with duodenum in two) and the gall bladder in two patients. It was not possible to make a preoperative diagnosis of biliary tract involvement in any of these patients. The lesions in the biliary tract were caused by the direct erosion by the necrotic tissue in five patients, and in one patient with gangrene of the gall bladder, it was a "remote" complication of the necrotizing process. All patients underwent surgery. Necrosectomy and cholecystectomy were performed in patients with gall bladder lesions, and proximal biliary drainage was the method of choice in patients with erosion of the bile duct. One patient died postoperatively. During follow-up, another patient who had bile-duct involvement developed a stricture in the damaged part of the bile duct and needed hepaticojejunostomy

CONCLUSIONS

Necrotizing pancreatitis can involve the biliary tract, both by direct extension and by its secondary effects. Although cholecystectomy is the treatment of choice in the presence of gallbladder involvement, proximal biliary diversion may be indicated in patients with erosion of the bile duct.

Optical resolution of (+/-)-1-aryl-1-alkanols using enantioselective transesterification by lipases

Enantioselective transesterification of 1-phenyl-1-alkanols (PhCH(OH)(CH2)n-2CH3; n = 2, 3, 4, 5, 6, 9, 12, 18) with vinyl acetate catalyzed by lipases in benzene has been studied to find the catalyst which is generally used for preparing optically active 1-phenyl-1-alkanols having various alkyl chains. Amongst lipases examined (lipases LIP, PS, AK, CAL and RML), the lipase from Pseudomonas aeruginosa (LIP) is the best catalyst which shows high reactivity and enantioselectivity and low substrate specificity. The rate of the LIP-catalyzed transesterification decreases with increasing the alkylchain length till n = 4. The catalysis of LIP recovers again toward the alkanols with n = 5-18. Other lipases do not exhibit such an effect of alkyl-chain length and show very poor or no catalysis for the alkanols with n > or = 4. LIP is also the best catalyst for the enantioselective transesterification of 1-(1-naphthyl)-, 1-(2-naphthyl)- and 1-(1-pyrenyl)-1-propanols. Each optically pure 1-aryl-1-alkanol was isolated by the present method.

Optical resolution of 1-arylethanols using transesterification catalyzed by lipases

The enantioselective transesterification of various 1-arylethanols with vinyl acetate catalyzed by lipases has been studied in benzene. The phenyl, pyridyl, naphthyl, quinoryl, anthryl, phenanthryl and pyrenyl groups were used as the aryl groups. Amongst various lipases examined, the lipase from Candida antarctica (lipase CAL) is the best catalyst which shows high enantioselectivity and low substrate specificity.

[Ultrasonographic evaluation of shoulder joints in hemodialysis patients]

Dialysis-related amyloidosis (DRA) is a serious complication in patients receiving long-term hemodialysis. Intrigued by the fact that the shoulder joint is primarily favored by DRA, we measured the shoulder-capsular distance (SCD) by ultrasonography to investigate the relationship between SCD and the duration of hemodialysis, patient age and biochemistry findings. The SCD of patients receiving hemodialysis was significantly increased, and there was a positive correlation between SCD and the duration of hemodialysis. The SCD tended to show a significant increase in patients receiving long-term hemodialysis over 10 years. Although the SCD was not significantly correlated with serum levels of beta 2-microglobulin and C-PTH, there was a significant positive correlation between the SCD and the serum levels of AI. In patients receiving long-term hemodialysis for 10 years or more, the SCD was increased significantly in the groups patients with the complications of carpal tunnel syndrome (CTS), cystic radiolucencies (CRL) or destructive spondyl arthropathy (DSA) compared with the value in complication-free patients. The results of this study suggest that the majority of patients with SCD > 8mm had the complication of DRA. Since ultrasonography is a non-invasive, east-to-perform procedure, ultrasonographic measurement of the SCD seems to be useful in the diagnosis of DRA.

Studies on orally active cephalosporins. I. Synthesis and structure-activity relationships of new 3-substituted carbamoyloxymethyl cephalosporins

The synthesis and antibacterial activities of 7 beta-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-N,N - dimethylcarbamoyloxymethyl-3-cephem-4-carboxylic acid (E1100) and its analogs are described, as well as oral absorbability and in vivo activities of the 1-(isopropoxycarbonyloxy)ethyl ester (E1101) and its analogous esters. The introduction of acyclic and cyclic lower alkyl groups at the N-position of 3-carbamoyloxymethyl cephems influences antibacterial activities, especially against H. influenzae, and oral absorbability of their prodrug esters. The structure-activity relationships are also discussed.

Studies on orally active cephalosporins. II. Synthesis and structure-activity relations of new [(E) or (Z) 3-substituted carbamoyloxy]-1-propenyl cephalosporins

In an effort to find a new oral cephalosporin with well-balanced antibacterial spectrum, good oral absorbability and long plasma half-life, a series of oxyimino aminothiazolyl 3-[(E)- or (Z)-N-substituted carbamoyloxy]propenyl cephems was synthesized and evaluated for antibacterial activity and oral absorbability. The substituents of the carbamoyloxy group affected their in vitro activity and bioavailability after oral administration of their pivaloyloxymethyl esters at the C-4 position. The compound possessing an N,N-dimethylcarbamoyloxy moiety at the C-3 position showed good oral absorption and well-balanced antibacterial activity. In this report, the structure-activity relationships and the structure-oral absorbability relationships of 3-(N-substituted carbamoyloxy)-propenyl cephems are described.

Common nitrogen control of caesium uptake, caesium toxicity and ammonium (methylammonium) uptake in the cyanobacterium Nostoc muscorum

Studies were carried out to examine the role of ammonium transport activity in the control of caesium uptake and toxicity in Nostoc muscorum. The results showed a definite specific role of the ammonium-repressible/derepressible ammonium transport system of the cyanobacterium in caesium uptake, accumulation and toxicity. Furthermore, the results showed that N. muscorum can acquire resistance against diazotrophically-associated caesium toxicity when supplied with ammonium as a nitrogen source. In addition, alternatively, a mutant strain was Cs-resistant in the absence of any effect on NH(+4)-transport, suggesting that Cs+ resistance may be determined at more than one cellular site.

Mutational analysis of the NH4+-nitrogen controls that regulate ammonium transport activity, heterocyst differentiation, nitrogenase activity and the heterocyst-spacing pattern in the cyanobacterium Nostoc muscorum

Mutational analysis of the genetic determinants mediating NH(4+)-nitrogen regulating effects on NH(4+)-transport activity, heterocyst differentiation, nitrogenase activity and heterocyst pattern formation was carried out in Nostoc muscorum. Evidence suggested the operation of three separate genetic determinants in such nitrogen control; one mediating NH(4+)-repression control on both heterocyst formation and NH(4+)-transport activity, a second (Nif-R) mediating NH(4+)-repression control on nitrogenase synthesis/activity and a third (Pat-R) essential for intercalary heterocyst formation/distribution. Ammonia itself functioned as repressor signal of heterocyst formation and nitrogenase synthesis/activity and the glutamine synthetase enzyme played no role in the repression/derepression control of heterocyst development and functional nitrogenase formation.

Inactivation of bacteria in sewage sludge by gamma radiation

The survival of certain bacterial cultures suspended in sewage sludge and exposed to gamma-radiation was studied. The inactivation patterns of most of the organisms were significantly different when irradiation was performed using sewage samples collected in the summer and monsoon seasons. The summer sample collected from the anaerobic digestor afforded significant protection to both Gram negative and Gram positive organisms. This was evident by the increase in dose required to bring about a 6 log cycle reduction in viable count of the bacterial cultures, when suspended in sewage samples instead of phosphate buffer. The observations made using monsoon digestor samples were quite different. This sewage sludge greatly enhanced inactivation by gamma-radiation in most cases. The effects of certain chemicals on the inactivation patterns of two organisms-Salmonella typhi and Shigella flexneri-were examined. Arsenate, mercury and lead salts sensitised S. typhi, while barium acetate and sodium sulphide protected this culture against gamma-radiation. In the case of Sh. flexneri, barium acetate and iodacetamide proved to be radioprotectors. The effects of some chemicals on the inactivation pattern of Sh. flexneri cells irradiated in sludge are also discussed.