A global inventory of photovoltaic solar energy generating units.

Photovoltaic (PV) solar energy generating capacity has grown by 41 per cent per year since 20091. Energy system projections that mitigate climate change and aid universal energy access show a nearly ten-fold increase in PV solar energy generating capacity by 20402,3. Geospatial data describing the energy system are required to manage generation intermittency, mitigate climate change risks, and identify trade-offs with biodiversity, conservation and land protection priorities caused by the land-use and land-cover change necessary for PV deployment. Currently available inventories of solar generating capacity cannot fully address these needs1-9. Here we provide a global inventory of commercial-, industrial- and utility-scale PV installations (that is, PV generating stations in excess of 10 kilowatts nameplate capacity) by using a longitudinal corpus of remote sensing imagery, machine learning and a large cloud computation infrastructure. We locate and verify 68,661 facilities, an increase of 432 per cent (in number of facilities) on previously available asset-level data. With the help of a hand-labelled test set, we estimate global installed generating capacity to be 423 gigawatts (-75/+77 gigawatts) at the end of 2018. Enrichment of our dataset with estimates of facility installation date, historic land-cover classification and proximity to vulnerable areas allows us to show that most of the PV solar energy facilities are sited on cropland, followed by aridlands and grassland. Our inventory could aid PV delivery aligned with the Sustainable Development Goals.

Patient and technique survival on peritoneal dialysis in patients with failed renal allograft: a case-control study.

Failed renal allograft is becoming one of the most frequent causes of dialysis initiation in countries with developed transplant programs. The majority of patients initiate hemodialysis (HD) as their next renal replacement modality and concerns about the success of peritoneal dialysis (PD) in this patient population has been expressed. We evaluated patient and technique outcome in a cohort of 494 patients in the United States who initiated PD after a failed renal allograft in the years 2000-2003, and compared the outcomes to those of two case-matched groups: patients new to dialysis or patients transferred from HD who started PD during the same period. Patients starting PD after a failed allograft had patient survival and technique survival similar to case-matched controls. Transplantation was lower in patients with failed allograft than controls. The high success of PD in patients with failed allograft suggests that it is beneficial to utilize this modality more frequently in this patient group than current practice.

Peritoneal dialysis in the US: evaluation of outcomes in contemporary cohorts.

Secular trends in dialysis therapy delivery require a frequent re-examination of outcomes in patients on renal replacement modalities. We examined four large cohorts of patients initiating peritoneal dialysis (PD) in 2000-2003 (total of >40 000 patients) to ascertain trends in patient outcomes, technique success, and predictors of both parameters of interest. Age, end-stage renal disease vintage, and diabetes were clear predictors of patient survival. Technique success was higher in patients on automated PD than in patients on continuous ambulatory PD. Center size was a powerful predictor of technique success. We conclude that the current state of PD in the United States is characterized by improving patient outcomes, higher technique success, and a predominance of use of cycler-based therapy. Several opportunities for improving technique success amenable to practice interventions have been identified.

A multinational clinical validation study of PD ADEQUEST 2.0. PD ADEQUEST International Study Group.

OBJECTIVE: To clinically validate the use of the newly released kinetic modeling program, PD ADEQUEST 2.0 for Windows (Baxter Healthcare Corporation, Deerfield, IL, U.S.A.), by assessing the level of agreement between measured and modeled values of urea and creatinine clearances (CCr), glucose absorption, total drain volumes, and net ultrafiltration for all forms of peritoneal dialysis. DESIGN: A nonrandomized, multinational, prospective longitudinal study. PATIENTS: The study involved 104 adult patients [41 on continuous ambulatory peritoneal dialysis (CAPD), 63 on automated peritoneal dialysis (APD)] from 16 centers in 7 countries. All patients underwent a 4-hour peritoneal equilibration test (PET) but with varying percentage dextrose concentrations (1.5% or 2.5% dextrose) and varying fill volumes (range 1.5 - 2.5 L). Patients with a residual renal function greater than 10 mL/min were excluded, as were patients who had peritonitis within 6 weeks prior to baseline. MAIN OUTCOME MEASURES: Correlation coefficients and Bland-Altman limits of agreement were used to assess the level of agreement between measured and modeled values of weekly peritoneal urea Kt/V (pKt/V) and total Kt/V, weekly peritoneal creatinine clearance (pCCr, L/week/1.73 m2) and total CCr (L/week/1.73 m2), daily drain volume (L/day), net ultrafiltration (UF, L/day), daily peritoneal urea and creatinine mass removal (g/day), and daily peritoneal glucose absorption (g/day). Measured values were obtained from three repeat 24-hour urine and dialysate collections per patient, while modeled values were calculated using the Baxter PD ADEQUEST 2.0 program in conjunction with kinetic parameters estimated from a 4-hour PET and long-dwell exchange independent of the 24-hour collections. RESULTS: The results show there is excellent agreement between measured and modeled urea Kt/V and CCr with concordance correlation coefficients ranging from 0.83 to 0.97 among CAPD and APD patients. There was also excellent agreement between measured and modeled values of glucose absorption and total drain volumes (concordance correlations of 0.90 and 0.98, respectively). This level of agreement was further supported by a Bland-Altman analysis of individual differences, including differences between measured and modeled net UF (coefficient of clinical agreement ranged from 0.66 to 0.92). CONCLUSIONS: Data from a carefully performed PET and overnight exchange can, in combination with a scientifically and clinically validated kinetic model, provide clinicians with a powerful mathematical tool for use in CAPD and APD prescription management. Although not intended to replace actual measurements, kinetic modeling can prove useful as a means for quickly estimating approximate levels of clearance for a wide variety of alternative prescriptions. This, in turn, should speed up the process by which a physician can optimize the dose of dialysis suitable for a given patient and his/her lifestyle.

Elevation of whole-blood glutathione in peritoneal dialysis patients by L-2-oxothiazolidine-4-carboxylate, a cysteine prodrug (Procysteine).

Glutathione is a major cellular antioxidant that protects protein thiols and inhibits cellular damage due to oxygen free radicals. It has been reported previously that patients undergoing dialysis have low levels of blood glutathione, which may lead to increased susceptibility to oxidant stress. L-2-oxothiazolidine-4-carboxylic acid (OTZ) is a cysteine prodrug that raises cellular glutathione levels by increasing delivery of cysteine, the rate-limiting substrate for glutathione synthesis. This study investigates the effect of OTZ on blood glutathione in a blinded, placebo-controlled study of patients with chronic renal failure treated by peritoneal dialysis. Twenty patients were randomly selected to receive OTZ (0.5 g three times a day orally with meals) or placebo for 14 d. Patients visited the clinic for predose blood collection and safety evaluation at baseline (days 3, 7, and 14 and again at 14 d from the last dose [follow-up]). Glutathione concentrations were determined in whole blood by HPLC. OTZ resulted in a significant rise in whole-blood glutathione at days 7 (594 +/- 129 mumol/L) and 14 (620 +/- 108 mumol/L) compared with baseline (544 +/- 139 mumol/L) (P < 0.01 and P < 0.05, respectively). Glutathione was also significantly increased at days 7 and 14 when normalized by hematocrit (Hct) or hemoglobin to correct for anemic status (e.g., 20.7 +/- 5.7 mumol/L per % Hct [day 7] and 20.9 +/- 4.0 mumol/L per % Hct [day 14] versus 18.0 +/- 4.2 mumol/L per % Hct [baseline]; P < 0.05). Glutathione levels did not change in the placebo group at any patient visit, and levels in the OTZ-treated group returned to baseline at follow-up. There were no serious adverse events attributable to OTZ, and the drug appeared to be well tolerated by patients with renal failure treated by continuous ambulatory peritoneal dialysis. Our results show that OTZ increases blood glutathione levels, which may improve antioxidant status in dialysis patients.

Psychological variables and cancer pain.

Pain can cause both physical and psychological distress that has a negative impact on a patient's quality of life. The purpose of this descriptive study was to determine whether cancer patients (N = 60) with pain (n = 30) had higher scores of depression, anxiety, somatization, and hostility than did cancer patients without pain (n = 30). The study was conducted in a midwestern medical center hospital during a 9-month period. Psychological variables were measured using subscales of the Brief Symptom Inventory (BSI). Patients who reported pain completed the McGill Pain Questionnaire (MPQ) and Visual Analogue Scale. Significant positive correlations were found between total MPQ scores and all four subscales of the BSI (r = 0.60-0.78, p < 0.05). Patients with pain scored higher on all four subscales of the BSI, with significant differences occurring in somatization (t = 2.05, p < 0.05) and hostility (t = 1.93, p < 0.05). The findings suggest a relationship between pain intensity and psychological status. Nursing interventions aimed at reducing these factors may help to decrease the pain, in addition to then decreasing the psychological distress experienced by patients with cancer.

Efficacy of the National Cholesterol Education Program Step I diet. A randomized trial incorporating quick-service foods.

OBJECTIVE: To determine the effect of incorporating quick-service meals into a Step I diet on the achievement of the National Cholesterol Education Program (NCEP) guidelines and on the blood lipid response of hyperlipidemic subjects (as possibly, the achievement of, and adherence to, dietary goals may be assisted by the inclusion of familiar foods, instead of their exclusion). METHODS: This was a randomized, parallel design study in free-living subjects. Hypercholesterolemic men and women (low-density lipoprotein cholesterol [LDL-C] level, 3.36 to 5.69 mmol/L [130 to 220 mg/dL]) who were consuming a high-fat diet (> 33% of total calories from fat) were randomly assigned to either a traditional NCEP Step I diet (n = 44) or an NCEP Step I diet with the incorporation of frequent quick-service meals (NCEP-QS, n = 45). RESULTS: After 8 weeks of treatment, both groups similarly reduced their reported dietary intakes of energy (approximately 30%), total percent fat (approximately 8%), percent saturated fat (approximately 3%), and cholesterol (approximately 38% to 28%). Both groups also experienced a decrease in the levels of total serum cholesterol (NCEP Step I diet, 8%; NCEP-QS Step I diet, 3%) and LDL-C (NCEP Step I diet, 10%; NCEP-QS Step I diet, 4%). However, compared with the group receiving the NCEP-QS Step I diet, the subjects who were consuming the NCEP Step I diet showed a significantly greater reduction in their total serum cholesterol and LDL-C levels over time (P < .05). Weight loss was significantly correlated (P < .001) with the decrease in the total serum cholesterol and LDL-C levels for all subjects combined. CONCLUSIONS: Hyperlipidemic subjects who were consuming an NCEP Step I diet, with or without the incorporation of quick-service meals, experienced a significant decrease in their total serum cholesterol and LDL-C levels, body weight, and reported fat intake. The beneficial responses in lipid levels were modestly mitigated in the quick-service diet group.

A psyllium-enriched cereal for the treatment of hypercholesterolemia in children: a controlled, double-blind, crossover study.

Psyllium, a water-soluble fiber, has been shown to lower total serum and low-density-lipoprotein (LDL)-cholesterol concentrations in adult hypercholesterolemic subjects and may be effective in the treatment of hypercholesterolemia in children. The effects of a psyllium-enriched cereal were compared with a matched control cereal in a double-blind, crossover fashion in 25 children, 6-18 y old, with hypercholesterolemia. After an 8-wk diet-stabilization period, the subjects were randomly assigned to receive the active or control cereals for 6 wk, followed by a 6-wk washout period and a 6-wk crossover treatment period. Whereas no changes were noted in total and LDL-cholesterol concentrations during consumption of the control cereal, significant changes were seen during the psyllium-cereal periods [0.31 mmol/L (12.1 mg/dL) and 0.28 mmol/L (10.9 mg/dL); P = 0.03 and 0.01, respectively]. The psyllium-enriched cereal was well tolerated throughout the trial. Consumption of the psyllium-enriched cereal resulted in a modest 7% reduction in LDL-cholesterol concentrations compared with the control cereal when used in this pediatric hypercholesterolemic sample. Psyllium offers a potential adjunct to a low-fat diet for the treatment of hypercholesterolemia in the pediatric population because of its ease of incorporation into various foods.

Determination of L-2-oxothiazolidine-4-carboxylic acid (Procysteine) in human plasma by high-performance liquid chromatography.

A new high-performance liquid chromatographic (HPLC) method has been developed for the determination of the cysteine prodrug, L-2-oxothiazolidine-4-carboxylic acid (Procysteine), in human plasma. Samples were mixed with 5% metaphosphoric acid and the supernatants chromatographed using a reversed-phase analytical column. Procysteine was detected spectrophotometrically at 230 nm and quantitated by comparison with a standard curve of known amounts of Procysteine (20-1000 microM) in plasma. The coefficients of variation for 48.6 microM and 676 microM control pools were 6.5 and 4.0% respectively (n = 46). Deviations from the expected concentrations were less than 2%. The method has been utilized to evaluate the pharmacokinetics of a wide range of oral and intravenous doses.

The hypocholesterolemic effects of beta-glucan in oatmeal and oat bran. A dose-controlled study.

Oat cereals rich in the water-soluble fiber beta-glucan have been studied as a dietary therapy for hypercholesterolemia. To determine the hypocholesterolemic response of beta-glucan in the diet, 156 adults with low-density lipoprotein cholesterol (LDL-C) levels above 4.14 mmol/L (160 mg/dL) or between 3.37 and 4.14 mmol/L (130 and 160 mg/dL) with multiple risk factors were randomized to one of seven groups. Six groups received either oatmeal or oat bran at doses (dry weight) of 28 g (1 oz), 56 g (2 oz), and 84 g (3 oz). A seventh group received 28 g of farina (beta-glucan control). At week 6 of treatment, significant differences were found for both total cholesterol and LDL-C levels among the farina control and the treatment groups who were receiving 84 g of oatmeal, 56 g of oat bran, and 84 g of oat bran, with decreases in LDL-C levels of 10.1%, 15.9%, and 11.5%, respectively. Fifty-six grams of oat bran resulted in significantly greater reductions in LDL-C levels than 56 g of oatmeal. Nutrient analysis shows no difference in dietary fat content between these treatment groups; therefore, the higher beta-glucan content of oat bran most likely explains the significantly greater LDL-C reductions. A dose-dependent reduction in LDL-C levels with oat cereals supports the independent hypocholesterolemic effects of beta-glucan.

Inline fluid dynamics in piggyback and manifold drug delivery systems.

Inline mixing characteristics of primary and secondary i.v. solutions were evaluated for the piggyback and manifold systems. Dextrose (5%) and sodium chloride (0.9%) were used as markers for the primary and secondary solutions, respectively. With a 120-mL/hr flow rate, samples (up to 180) were collected over 36 minutes to quantify the change in concentration of each marker when the primary solution was changed to the secondary solution (phase 1) and when the secondary solution was changed to the primary solution (phase 2). The relative concentration data for each marker were fitted to a Weibull mathematical model to describe the disappearance and appearance of the two solutions over time. These data were then used to calculate the volume of secondary solution that was mixed with the primary solution in phases 1 and 2. With the piggyback system, the total mixing volume was 13.5 mL, with 11.1 mL contributed by the secondary solution (phase 1). In phase 2, the total mixing volume decreased to 6.6 mL, with 2.0 mL contributed by the secondary solution. The mixing volumes for the manifold system were markedly reduced; 5.8 mL of the secondary solution became mixed with 1.9 mL of the primary solution. The total mixing volume during phase 1 was reduced from 13.5 to 5.6 mL. The mixing volumes for the primary, secondary, and total solutions in phase 2 were comparable to those with the piggyback system. The use of manual clamps or automated line closures as part of a manifold system can substantially reduce the mixing of solutions inline, compared with a piggyback system.

Stability of procainamide hydrochloride in neutralized 5% dextrose injection.

The stability of procainamide hydrochloride in neutralized 5% dextrose injection was studied. Sixty-four admixtures were prepared by adding either 2 mL (for 0.4% admixtures) or 4 mL (for 0.8% admixtures) of procainamide hydrochloride to 250 mL of 5% dextrose injection in plastic containers. The pH of 32 of these admixtures (16 of each type) was adjusted to 7.5. These 32 admixtures represented the neutralized group, and the remaining 32 represented the control group. The admixtures were stored at either 23-25 degrees C (room temperature) or 5 degrees C (refrigeration) for 24 hours. Procainamide hydrochloride concentrations in each sample were determined by high-performance liquid chromatography immediately after the admixtures were prepared and at various intervals during storage. Procainamide concentrations decreased over time in 5% dextrose injection. The decrease was significantly less for admixtures in neutralized 5% dextrose injection, those stored under refrigeration, and those with an 0.8% concentration of drug. Decreases in procainamide hydrochloride concentrations in the control admixtures might have been caused by procainamide-dextrose complexation. Initial concentrations of procainamide hydrochloride in 5% dextrose injection can be adequately maintained over a 24-hour storage period by neutralizing the 5% dextrose injection or storing the admixture at 5 degrees C. However, because it is impractical to maintain the necessary temperature condition during a 24-hour infusion, neutralization might be the most viable alternative when extended stability of procainamide hydrochloride in 5% dextrose injection is required.

Effect of silver oxide/trichloroisocyanuric acid antimicrobial urinary drainage system on catheter-associated bacteriuria.

We assessed the efficacy of silver oxide coating of the indwelling urethral catheter and catheter adapter, and instillation of trichloroisocyanuric acid into the urinary drainage bag in the prevention of catheter-associated bacteriuria in a prospective and randomized study of 74 patients. Bacteriuria was documented in 29 of the 74 patients (39 per cent). There was a significant difference between the attack rates, with 11 of 41 patients (27 per cent) in the test group and 18 of 33 (55 per cent) in the control group having bacteriuria (p equals 0.02) after a median time to bacteriuria of 36 and 8 days, respectively (p equals 0.01). Urethral meatal colonization was implicated as the source of bladder bacteriuria in 12 of 18 patients (67 per cent) in the control group and 5 of 11 (45 per cent) in the test group. Trichloroisocyanuric acid significantly reduced drainage bag contamination but bag contamination with the same microorganism responsible for bacteriuria preceded infection in only 2 of the 29 patients (7 per cent), 1 in each group. Patients who received systemic antimicrobial agents acquired bacteriuria less frequently than those who did not. The apparent protective effect of systemic antimicrobials was strongest during the first 4 days of catheterization. The data indicate that episodes of bacteriuria arising from the urethral meatus are common among catheterized patients and that the antimicrobial catheter is effective in reducing the incidence of catheter-associated bacteriuria.

The effect of pilocarpine on the visual field in normals.

Despite generalized consensus that pilocarpine-induced miosis results in some degree of visual field constriction, studies describing the predictability of this occurrence, as well as the nature of the field defects that may be seen, have not been undertaken. We studied 20 normal subjects, ranging in age from 24 to 57 years. Baseline refraction, pupillary measurements, and visual fields were performed in both eyes on a standardized Goldmann perimeter with the I-2e, I-3e, and I-4e test objects. Pilocarpine 2% was then instilled into the study eye and the field repeated at 30 and 120 minutes. An IBM PC computer program, designed by the authors, was used to calculate the area contained within each isopter. The probability of visual field constriction at 30 and 120 minutes after instillation of pilocarpine was found to be significant, especially with pupillary diameters of 2 mm or less. The I-2e isopter was most sensitive to miosis. Visual field constriction persisted with correction of ciliary spasm induced myopia, suggesting that miosis, especially when marked, can independently alter the visual field. The clinician, then, should make every effort to control visual field testing conditions in glaucoma patients on miotics to allow reliable serial comparisons.

Local hyperthermia in combination with definitive radiotherapy: increased tumor clearance, reduced recurrence rate in extended follow-up.

Fifty-nine patients with superficial malignancies appropriate for treatment with definitive radiotherapy and technically suitable for application of local microwave hyperthermia were available for at least 6 months follow-up. Thirty-one of these patients presented with two lesions, only one of which was heated, the other serving as internal control. The responses of the lesions which were heated were compared with those receiving only radiation. The heated lesions responded more quickly, reconfirming observations previously made. However, at subsequent 6 months, 1 year, 18 months and 2 years follow-ups, tumor clearance was shown to be significantly more complete as compared with the internal controls. At 6 months follow-up complete response with combined therapy was observed in 27 of 31 lesions (87%) in contrast to complete response in 12 of 31 (39%) lesions treated with radiotherapy alone. At one year combined modality treatment produced complete response in 19 of 19 lesions (100%) while radiotherapy alone yielded complete response in 10 of 19 lesions (53%). At 18 months, 8 of 9 lesions (89%) treated with combined therapy remained controlled, 1 having recurred. Seven of 9 (78%) treated by radiotherapy alone were controlled, 2 having recurred. At 2 years, 6 patients were available for follow-up and 6 of 6 (100%) of lesions treated with combined modality remained controlled. Among those treated by radiotherapy alone, 5 of 6 (83%) remained controlled, while 1 recurred. The rate of tumor recurrence among the heated lesions was significantly lower than was found among the controls. The recurrence rate among the controls was similar to that expected in a similar group of patients treated with definitive radiotherapy. Therefore, in addition to its established capability to shrink tumors, hyperthermia in combination with radiotherapy has been shown to increase the rate of overall tumor clearance and reduce recurrences compared with that obtained from radiotherapy alone.

Hyperthermia in combination with radiotherapy: a review of five years experience in the treatment of superficial tumors.

Facilities for regional tumor hyperthermia has been in use at RPMI since 1976, and have been routinely used to treat patients according to protocol since 1977. Hyperthermia delivery has been exclusively by microwave using 434 MHz, 915 MHz and 2450 MHz. Greatest success at reaching tumor temperatures of 43-44 degrees C with minimal skin heating was obtained using 915 MHz. The majority of the patients were treated with this frequency. Approximately 125 patients have been treated and 70 have achieved completion of therapy and follow-up. Follow-up has been at least one month and several patients have been followed for one to two years. Initially, for entry into the hyperthermia protocol, patients were required to have three or more lesions. One lesion on each patient was treated with 800 rad fractions repeated three times on a 72 hour schedule. The second lesion was treated with 700 rad fractions and the third with 500 rad plus hyperthermia on the same schedule. Twelve patients with multiple melanoma lesions completed this study. One of 12 patients showed no response to the combination of hyperthermia plus radiotherapy, while four showed no response to radiotherapy alone. Of eight patients who survived three months, all lesions treated by hyperthermia plus radiotherapy responded completely, while only five lesions treated by radiotherapy alone so responded. In a second study, 58 patients with superficial tumors were treated by a protocol where hyperthermia was added to optimal conventional radiotherapy. Of the total, 43 patients had complete tumor response at follow-up varying from one month to 18 months. A subgroup of 24 of these patients had two lesions, one of which was treated with hyperthermia in addition to radiotherapy while the other served as control, receiving radiotherapy only. Nineteen lesions demonstrated complete response to hyperthermia plus radiotherapy, while only 14 of the controls had complete response. None of the lesions treated with hyperthermia responded less well than those treated by radiotherapy alone. Morbidity, as measured by skin reaction, was rarely increased in the heated field.

Relative potencies of four reference endotoxin standards as measured by the Limulus amoebocyte lysate and USP rabbit pyrogen tests.

Four commonly used reference endotoxin standards, Escherichia coli O113:H10:K0, E. coli O55:B5, Salmonella abortusequi, and Shigella dysenteriae were compared by the USP rabbit pyrogen and the Limulus amoebocyte lysate tests. By the rabbit pyrogen test, S. abortus equi was identified as the most potent endotoxin, followed closely by E. coli O113:H10:K0 and E. coli O55:B5.