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Nitrogen (N) loss through ammonia $$({\mathrm{NH}}_{3})$$ volatilization in agricultural soils is a significant source of atmospheric $${\mathrm{NH}}_{3}$$ , contributing to low N use efficiency in crops, risk to human health, environmental pollution, and is an indirect source of nitrous oxide $$({\mathrm{N}}_{2}\mathrm{O})$$ emissions. Our objective was to develop an ammonia volatilization method within the DayCent ecosystem model that incorporates key 4R N management practices (right type, right rate, right placement, and right timing) that influence $${\mathrm{NH}}_{3}$$ volatilization associated with application of urea-based nitrogen fertilizers to agricultural soils. The $${\mathrm{NH}}_{3}$$ volatilization method was developed with Bayesian calibration using sampling importance resampling methods and Bayes factors to select the level of complexity in the model that best represents $${\mathrm{NH}}_{3}$$ volatilization given the observed data. The final model included urea hydrolysis and the influence of urease inhibitors; short-term soil pH changes following fertilization; fertilizer incorporation into the soil (mechanically and through irrigation/precipitation); and specification of the fertilizer placement method (i.e. broadcast vs. banding and surface vs incorporated). DayCent predicts $${\mathrm{NH}}_{3}$$ volatilization with a root-mean-squared error of 158 (95% interval ranging from 133 to 192), bias of 7 (95% interval ranging from − 106 to 102) g NH3-N ha−1 day−1, and with a Bayesian R2 value of 0.39 (95% interval ranging from 0.17 to 0.62). Furthermore, the model incorporates key management options influencing $${\mathrm{NH}}_{3}$$ volatilization related to placement method and fertilizer type with and without urease inhibitors that can be used to evaluate management and policy options for reducing losses of NH3 from urea fertilization.

Alternative sources of neutron production other than nuclear fission reactions are important priorities in medical and nuclear applications due to costs, safety and ease of operation. In this work, $$^{12}\hbox {C}$$ and $$^{13}\hbox {C}$$ thick targets for neutron production through $$^{12}\hbox {C(d,n)}^{13}\hbox {N}$$ and $$^{13}\hbox {C(d,n)}^{14}\hbox {N}$$ , respectively, have been manufactured and characterized by different techniques. In order to evaluate the irradiation effects on these materials, the targets were irradiated with 150 keV proton beam. A complete characterization of these samples was performed using scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, Auger electron spectroscopy, X-ray photoemission spectroscopy and Raman spectroscopy. The results of these studies allowed us to establish that even though the irradiated samples present microstructural and chemical structure changes on its surface, the $$^{12}\hbox {C}$$ and $$^{13}\hbox {C}$$ thick targets were stable and would maintain their performance after proton irradiation at a fluence of $$2.0\times 10^{18}\hbox { ions/cm}^{2}$$ and $$3.7\times 10^{18}\hbox { ions/cm}^{2}$$ , respectively.

To meet clinicians’ request for adequate results and reliable reference ranges for testosterone, this study was planned with the aims (i) to verify the reliability of the reference interval for total testosterone (TT) declared by immunoassay manufacturer and adopted by laboratory, (ii) to compare results for serum TT obtained by immunoassay and LC–MS/MS and (iii) to verify if the cutoff values for low TT and measured free testosterone (FT), defined by Endocrine Society Guidelines for diagnosis of hypogonadism, are applicable to our study group. Sera from anonymous young/middle-aged male blood donors were selected for the study. TT was measured by immunoassay and LC–MS/MS. SHBG was measured by immunoassay and used with albumin concentration to calculate FT according to Vermeulen’s formula. The reference interval declared by the manufacturer and adopted by the lab was validated. The two methods for TT evaluation correlated very well. TT and FT lower limits at 5th and 2.5th percentile are below the cutoffs reported in the literature for the diagnosis of hypogonadism. The immunoassay currently used in our lab can be considered an adequate tool for TT, but it’s essential that clinical data agree with the biochemical ones, particularly in the presence of TT values between the lower limit of reference range and the cutoff values recommended by scientific societies.

We focus on the development of well-balanced Lagrange-projection schemes applied to the one-dimensional blood flow system of balance laws. Here we neglect the friction forces and the source term is due to the presence of varying parameters as the cross-sectional area at the equilibrium and the arterial stiffness. By well-balanced we mean that the method preserves the “man at eternal rest” solution. For this purpose we present two different strategies: the former requires a consistent definition of the source term based on an approximate Riemann solver, while the second one exploits the well-established hydrostatic reconstruction. Subsequently we explain how to reach the second-order of accuracy for both procedures. Numerical simulations are carried out in order to show the right order of accuracy and the good behaviour of the schemes.

Best management practices for N fertilization should increase yields while reducing negative environmental effects such as losses by ammonia (NH3) volatilization and emission of greenhouse gases, especially nitrous oxide (N2O). We studied the impact on sugarcane of two N sources (UR: urea and CAN: calcium ammonium nitrate) in three N rates (30, 60, and 90 kg N ha−1 in the plant cane cycle and 60, 120, and 180 kg N ha−1 in ratoons) on a sugarcane field grown on a Red Latosol soil in southeastern Brazil. We measured sugarcane yields and N2O, CO2 and CH4 emissions in three crop cycles (plant cane, 2nd and 3rd ratoons), and NH3 in two crop cycles (2nd and 3rd ratoons). The accumulated emission of N2O from UR was significantly higher in comparison with those of CAN in all three crop cycles. The average emission factors for UR were 0.8% (plant cane), 1.1% (2nd ratoon) and 0.8% (3rd ratoon) and the corresponding figures for CAN were 0.4%, 0.7% and 0.5%, respectively. The N2O intensity was higher for UR (20.3 mg N–N2O kg−1 sugarcane stalk) than CAN (16.2 mg N–N2O kg−1 sugarcane stalk). The NH3 volatilization losses for CAN were less than 1% compared to 5–16% of the N applied as UR. Stalk yield increased with N application, but no difference was observed between UR and CAN. We concluded that CAN has the potential to reduce both NH3 and N2O losses compared with urea and is the preferred N source for sugarcane.

Sugarcane straw is a source of carbon (C) and nitrogen (N), which affect soil temperature and moisture and therefore soil nitrous oxide (N2O) emissions from fertilized fields. The use of a nitrification inhibitor (NI) with N fertilizers is an option to reduce N2O production; however, sugarcane straw may interfere with the efficiency of a NI to reduce these losses. We conducted two laboratory studies over nearly 100 days to evaluate the following: (i) the implications of sugarcane straw removal and N fertilization under different temperatures on N2O emissions and (ii) the efficiency of a NI to reduce N2O emissions as determined by straw rates. In the first experiment, the treatments were as follows: N (0 and 100 kg ha−1), straw (0 and 8 Mg ha−1), and soil temperature (20 and 30 °C); in experiment 2, we included another straw rate (16 Mg ha−1) and NI dicyandiamide (DCD) (10 kg ha−1). Straw increased N2O emissions from N fertilizer by 37-fold and 3-fold in experiments 1 and 2, respectively. The N2O emissions were 62% higher at 20 °C than at 30 °C, whereas the opposite was observed for CO2 emissions. There was a synergistic effect of straw, which increased the dissolved organic C by more than 50% in the topsoil layer and was positively correlated with N2O emissions. The NI strongly reduced N2O emissions (> 63%) regardless of the straw rate, with no effect on soil respiration. The use of NI is an important strategy to mitigate N2O emissions from N fertilization in sugarcane fields where harvest residues are preserved.

The emerging field of RNA nanotechnology harnesses the versatility of RNA molecules to generate nature-inspired systems with programmable structure and functionality. Such methodology has therefore gained appeal in the fields of biosensing and diagnostics, where specific molecular recognition and advanced input/output processing are demanded. The use of RNA modules and components allows for achieving diversity in structure and function, for processing information with molecular precision, and for programming dynamic operations on the grounds of predictable non-covalent interactions. When RNA nanotechnology meets bioanalytical chemistry, sensing of target molecules can be performed by harnessing programmable interactions of RNA modules, advanced field-ready biosensors can be manufactured by interfacing RNA-based devices with supporting portable platforms, and RNA sensors can be engineered to be genetically encoded allowing for real-time imaging of biomolecules in living cells. In this article, we report recent advances in RNA-based sensing technologies and discuss current trends in RNA nanotechnology-enabled biomedical diagnostics. In particular, we describe programmable sensors that leverage modular designs comprising dynamic aptamer-based units, synthetic RNA nanodevices able to perform target-responsive regulation of gene expression, and paper-based sensors incorporating artificial RNA networks. Graphical Abstract ᅟ.

Biofuels vary greatly in their carbon intensity, depending on the specifics of how they are produced. Policy frameworks are needed to ensure that biofuels actually achieve intended reductions in greenhouse gas emissions. Current approaches do not account for important variables during cultivation that influence emissions. Estimating emissions based on biogeochemical models would allow accounting of farm-specific conditions, which in turn provides an incentive for producers to adopt low emissions practices. However, there are substantial uncertainties in the application of biogeochemical models. This paper proposes a policy framework that manages this uncertainty while retaining the ability of the models to account for (and hence incentivize) low emissions practices. The proposed framework is demonstrated on nitrous oxide (N2O) emissions from the cultivation of winter barley. The framework aggregates uncertainties over time, which (1) avoids penalizing producers for uncertainty in weather, (2) allows for a high degree of confidence in the emissions reductions achieved, and (3) attenuates the uncertainty penalties borne by producers within a timescale of several years. Results indicate that with effective management, N2O emissions from feedstock cultivation may be 20% of the carbon intensity of gasoline. If these emissions reductions are monetized, the framework can provide up to $0.002 per liter credits (0.8 cents per gallon) to fuel producers, which could incentivize emissions mitigation practices by biofuel feedstock suppliers, such as avoiding fall N application on silty clay loam soils. The conservatism in the current approach fails to incentivize the adoption of biofuels, while the lack of specificity fails to incentivize site-level mitigation practices. Improved uncertainty accounting and consideration of farm-level practices will incentivize mitigation efforts at landscape to global scales.

Carbazochrome (2-(1,2,3,6-tetrahydro-3-hydroxy-1-methyl-6-oxo-5H-indol-5-ylidene)-hydrazinecarboxamide, CBZ) and carbazochrome sodium sulfonate (5-[(aminocarbonyl)hydrazono]-2,3,5,6-tetrahydro-1-methyl-6-oxo-1H-indole-2-sulfonic acid sodium salt, CSS) are derivatives of adrenochrome currently employed mainly as hemostatic drugs. Since a semicarbazone group is present in both the structures of CBZ and CSS, semicarbazide hydrochloride (SEM) is used, as reagent, in their synthesis. Belonging to the hydrazine family of chemicals, SEM could possess some toxic potential. Accordingly, literature data showed that SEM causes osteolathyrism and induces toxic effects in the cardiovascular and skeletal systems. Moreover, SEM has a weak genotoxic activity in vitro while in vivo available data are not sufficient to state its genotoxicity. Based on these data, the determination of SEM as a synthesis-related impurity in CBZ and CSS drug substances is mandatory. Since there are no publications dealing with the determination of SEM in CBZ and CSS as well as in any other SEM-containing drugs, a new and unprecedented LC-DAD-UV method for its determination as impurity in CBZ and CSS drug substances was developed and validated. Due to the lack of chromophore, semicarbazide was converted into the corresponding UV-absorbing naphthalene-2-carbaldehyde semicarbazone (NCS) before the chromatographic analysis. The complete separation of NCS from the large concentration of the derivatization reagent and the parent drugs CBZ and CSS was accomplished through a liquid–liquid extraction (LLE) step followed by a chromatographic run of 10 min. The method was then successfully validated and its applicability demonstrated by the determination of SEM in real samples of CBZ and CSS.

The consolidating adhesive project is an international collaboration which aims to develop a new adhesive with well characterized physical, optical, and ageing characteristics specific for the consolidation of painted layers. Since starting in 2010, many findings have been made, and new useful polymer-tackifier, and polymer-tackifier-wax blends have been tested. The concept of component miscibility and the effect it has on the final properties of the adhesive is complex, but fundamental to the development of a new product. To quantify the properties conservators most need, the initial focus was on understanding BEVA® 371, a widely used poly(ethylene vinyl acetate) based heat-seal adhesive. It was originally developed as a lining adhesive for paintings, and has been adapted by conservators for a variety of consolidating applications; however, its ideal consolidation performance properties are starting to be out-weighed by concerns regarding its long-term stability, as well as recent formulation changes. There is a need for a new adhesive tailored to the requirements of the conservation field. This paper will discuss the results obtained thus far, and the goals for the future. The project is entering a new phase, where we hope to continue to explore new blends, and have conservator testing on painting mock-ups.

Serotyping of Streptococcus pneumoniae is essential for monitoring changes in the pneumococcal population and the impact of vaccines. Recently, various DNA-based methods have become available and are increasingly used because they are cheaper and easier to perform than the Quellung reaction. Our aim was to apply a DNA-based method, capsular sequence typing (CST), to a collection of non-viable lyophilized pneumococcal isolates dating from the 1980s to elucidate the serotypes circulating in Italy 30 years ago. As a preliminary evaluation of the method, CST was applied to 68 recent pneumococcal isolates representative of the most common serotypes circulating in Italy in invasive pneumococcal disease (IPD) previously serotyped by the Quellung reaction. CST was then applied to 132 lyophilized non-viable isolates. A serotype-specific polymerase chain reaction (PCR), using primers suggested by the Centers for Disease Control and Prevention (CDC), was performed when CST did not yield a univocal serotype. Considering the control isolates, CST concordance with the Quellung reaction was 95.6 %. For the non-viable lyophilized isolates, CST identified a univocal serotype for 59.4 % of the isolates. This percentage increased to 78.1 % if CST was combined with serotype-specific PCR. The most frequent serotypes in the collection of non-viable strains were: 3 (15.6 %), 14 (11.7 %), 35B (5.5 %), 19A (5.5 %), and 8 (4.7 %). CST proved to be a valid method for serotyping pneumococcal strains and provided information about pneumococcal serotypes present in Italy 30 years ago. The combination of CST with serotype-specific PCR was an effective strategy to identify pneumococcal serotypes that can be suggested also for routine laboratories.

Public policies are promoting biofuels as an alternative to fossil fuel consumption in order to mitigate greenhouse gas (GHG) emissions. However, the mitigation benefit can be at least partially compromised by emissions occurring during feedstock production. One of the key sources of GHG emissions from biofuel feedstock production, as well as conventional crops, is soil nitrous oxide (N2O), which is largely driven by nitrogen (N) management. Our objective was to determine how much GHG emissions could be reduced by encouraging alternative N management practices through application of nitrification inhibitors and a cap on N fertilization. We used the US Renewable Fuel Standards (RFS2) as the basis for a case study to evaluate technical and economic drivers influencing the N management mitigation strategies. We estimated soil N2O emissions using the DayCent ecosystem model and applied the US Forest and Agricultural Sector Optimization Model with Greenhouse Gases (FASOMGHG) to project GHG emissions for the agricultural sector, as influenced by biofuel scenarios and N management options. Relative to the current RSF2 policy with no N management interventions, results show decreases in N2O emissions ranging from 3 to 4 % for the agricultural sector (5.5–6.5 million metric tonnes CO2 eq. year−1; 1 million metric tonnes is equivalent to a Teragram) in response to a cap that reduces N fertilizer application and even larger reductions with application of nitrification inhibitors, ranging from 9 to 10 % (15.5–16.6 million tonnes CO2 eq. year−1). The results demonstrate that climate and energy policies promoting biofuel production could consider options to manage the N cycle with alternative fertilization practices for the agricultural sector and likely enhance the mitigation of GHG emissions associated with biofuels.

We evaluated the biogeochemical cycling and relative greenhouse gas (GHG) mitigation potential of proposed biofuel feedstock crops by modeling growth dynamics of Miscanthus × giganteus Greef et Deuter (miscanthus), Panicum virgatum L. (switchgrass), Zea mays L. (corn), and a mixed prairie community under identical field conditions. DAYCENT model simulations for miscanthus were parameterized with data from trial plots in Europe and Illinois, USA. Switchgrass, corn, and prairie ecosystems were simulated using parameters published in the literature. A previously unknown source of nitrogen (N) was necessary to balance the plant nutrient budget in miscanthus crops, leading us to hypothesize that miscanthus growth depends on N-fixation. We tested for nitrogenase activity by acetylene reduction of whole rhizomes and bacteria isolated from the rhizosphere and miscanthus tissue. Our results supported the hypothesis that biological N-fixation contributed to the N demand of miscanthus, a highly productive perennial grass. Corn agro-ecosystems emit 956 to 1899 g CO2eq m−2y−1 greater GHGs (including CO2, N2O, CH4) to the atmosphere than the other biofuel crop alternatives because of greater N2O emissions from fertilizer additions. Of the feedstock crops evaluated in this study, miscanthus would result in the greatest GHG reduction.

It is difficult to quantify nitrogen (N) losses from agricultural systems; however, we can use 15N isotopic techniques to conduct site-specific studies to increase our knowledge about N management and fate. Our manuscript analyzes two reviews of selected 15N isotopic studies conducted to monitor N fate. The mechanistic foci of these studies include crop residue exchange and N fate in farming systems. Analysis of the data presented in these studies supports the claim that the average N losses are greater from inorganic N fertilizer inputs than organic crop residue N inputs. Additionally we conducted unique DAYCENT simulations of the effects of crop residue on nitrous oxide (N2O-N) emissions and nitrate (NO3-N) leaching. The simulation evaluations support the crop residue 15N exchange studies and show lower leaching and N2O-N emissions from crop residue sources when compared to N fertilizer. The 15N data suggest that the N in the crop residue pool must be recycled, and that this is a slower and more protected pool when compared to the readily available fertilizer. The results suggest that the Intergovernmental Panel on Climate Change (IPCC) methodology should be reevaluated to determine whether the direct and indirect N2O-N emission coefficients need to be lowered to reflect fewer N2O-N emissions from high C/N crop residue N inputs. The data suggest that accounting for nutrient cycling has implications for public policy associated with the United Nations Framework Convention on Climate Change (UNFCCC) and mitigation of N2O-N emissions from agricultural soils. Additional crop residue exchange studies, field N2O-N and NO3-N leaching and support model evaluations are needed across different worldwide agroecosystems.

Denitrification is known as an important pathway for nitrate loss in agroecosystems. It is important to estimate denitrification fluxes to close field and watershed N mass balances, determine greenhouse gas emissions (N2O), and help constrain estimates of other major N fluxes (e.g., nitrate leaching, mineralization, nitrification). We compared predicted denitrification estimates for a typical corn and soybean agroecosystem on a tile drained Mollisol from five models (DAYCENT, SWAT, EPIC, DRAINMOD-N II and two versions of DNDC, 82a and 82h), after first calibrating each model to crop yields, water flux, and nitrate leaching. Known annual crop yields and daily flux values (water, nitrate-N) for 1993–2006 were provided, along with daily environmental variables (air temperature, precipitation) and soil characteristics. Measured denitrification fluxes were not available. Model output for 1997–2006 was then compared for a range of annual, monthly and daily fluxes. Each model was able to estimate corn and soybean yields accurately, and most did well in estimating riverine water and nitrate-N fluxes (1997–2006 mean measured nitrate-N loss 28 kg N ha−1 year−1, model range 21–28 kg N ha−1 year−1). Monthly patterns in observed riverine nitrate-N flux were generally reflected in model output (r 2 values ranged from 0.51 to 0.76). Nitrogen fluxes that did not have corresponding measurements were quite variable across the models, including 10-year average denitrification estimates, ranging from 3.8 to 21 kg N ha−1 year−1 and substantial variability in simulated soybean N2 fixation, N harvest, and the change in soil organic N pools. DNDC82a and DAYCENT gave comparatively low estimates of total denitrification flux (3.8 and 5.6 kg N ha−1 year−1, respectively) with similar patterns controlled primarily by moisture. DNDC82h predicted similar fluxes until 2003, when estimates were abruptly much greater. SWAT and DRAINMOD predicted larger denitrification fluxes (about 17–18 kg N ha−1 year−1) with monthly values that were similar. EPIC denitrification was intermediate between all models (11 kg N ha−1 year−1). Predicted daily fluxes during a high precipitation year (2002) varied considerably among models regardless of whether the models had comparable annual fluxes for the years. Some models predicted large denitrification fluxes for a few days, whereas others predicted large fluxes persisting for several weeks to months. Modeled denitrification fluxes were controlled mainly by soil moisture status and nitrate available to be denitrified, and the way denitrification in each model responded to moisture status greatly determined the flux. Because denitrification is dependent on the amount of nitrate available at any given time, modeled differences in other components of the N cycle (e.g., N2 fixation, N harvest, change in soil N storage) no doubt led to differences in predicted denitrification. Model comparisons suggest our ability to accurately predict denitrification fluxes (without known values) from the dominant agroecosystem in the midwestern Illinois is quite uncertain at this time.

We present a new soil respiration model, describe a formal model testing procedure, and compare our model with five alternative models using an extensive data set of observed soil respiration. Gas flux data from rangeland soils that included a large number of measurements at low temperatures were used to model soil CO2 emissions as a function of soil temperature and water content. Our arctangent temperature function predicts that Q10 values vary inversely with temperature and that CO2 fluxes are significant below 0 °C. Independent data representing a broad range of ecosystems and temperature values were used for model testing. The effects of plant phenology, differences in substrate availability among sites, and water limitation were accounted for so that the temperature equations could be fairly evaluated. Four of the six tested models did equally well at simulating the observed soil CO2 respiration rates. However, the arctangent variable Q10 model agreed closely with observed Q10 values over a wide range of temperatures (r2 = 0.94) and was superior to published variable Q10 equations using the Akaike information criterion (AIC). The arctangent temperature equation explained 16–85% of the observed intra-site variability in CO2 flux rates. Including a water stress factor yielded a stronger correlation than temperature alone only in the dryland soils. The observed change in Q10 with increasing temperature was the same for data sets that included only heterotrophic respiration and data sets that included both heterotrophic and autotrophic respiration.

Carbon sequestration in agricultural, forest, and grassland soils has been promoted as a means by which substantial amounts of CO2 may be removed from the atmosphere, but few studies have evaluated the associated impacts on changes in soil N or net global warming potential (GWP). The purpose of this research was to (1) review the literature to examine how changes in grassland management that affect soil C also impact soil N, (2) assess the impact of different types of grassland management on changes in soil N and rates of change, and (3) evaluate changes in N2O fluxes from differently managed grassland ecosystems to assess net impacts on GWP. Soil C and N stocks either both increased or both decreased for most studies. Soil C and N sequestration were tightly linked, resulting in little change in C:N ratios with changes in management. Within grazing treatments N2O made a minor contribution to GWP (0.1–4%), but increases in N2O fluxes offset significant portions of C sequestration gains due to fertilization (10–125%) and conversion (average = 27%). Results from this work demonstrate that even when improved management practices result in considerable rates of C and N sequestration, changes in N2O fluxes can offset a substantial portion of gains by C sequestration. Even for cases in which C sequestration rates are not entirely offset by increases in N2O fluxes, small increases in N2O fluxes can substantially reduce C sequestration benefits. Conversely, reduction of N2O fluxes in grassland soils brought about by changes in management represents an opportunity to reduce the contribution of grasslands to net greenhouse gas forcing.

The aim of this study was to determine the factors favouring Streptococcus pneumoniae nasopharyngeal colonization of healthy children attending daycare centres and to describe the circulation of penicillin-nonsusceptible strains using molecular techniques. A single nasopharyngeal swab was obtained from 610 children attending daycare centres in the southeast area of Rome. Streptococcus pneumoniae isolates were serotyped, and antibiotic susceptibility was assayed by the E test. The genetic determinants of erythromycin resistance were detected by a duplex polymerase chain reaction, and the penicillin-nonsusceptible isolates were typed by pulsed-field gel electrophoresis. The overall carriage rate of Streptococcus pneumoniae was 14.9%. Living with more than three persons in the same household was the only risk factor statistically associated with carriage. Sixteen of 85 (18.8%) strains were nonsusceptible to penicillin, and 44 (52%) were resistant to erythromycin. Of the erythromycin-resistant strains, the vast majority showed a high level of resistance and carried the erm(B) gene. The penicillin-nonsusceptible strains belonged to six different serotypes; molecular typing showed that in only one case (2 strains) was there a circulation of the same clone in the same daycare centre. In view of the high rate of resistant Streptococcus pneumoniae strains, risk factors for carriage of resistant strains were evaluated. Children who received macrolides in the previous month had a higher risk of being colonized by macrolide-resistant strains as well as by strains resistant to both penicillin and erythromycin. Limiting the use of antibiotics in children seems the most appropriate measure to control the spread of antibiotic-resistant strains.

Expansion of B cell precursors after unrelated cord blood transplantation for an adult patient

Thermogravimetry (TG), thermogravimetry/mass spectrometry (TG/MS), and loss-on-drying methodology are used to provide residual moisture results for freeze-dried biological products regulated by the US Food and Drug Administration. Residual moisture specifications must be met in order to ensure freeze-dried biological product potency and stability throughout the licensed product's shelf life. TG, TG/MS, loss-on-drying and vapor pressure moisture measurements are compared for a BCG Vaccine. Comparisons are made between residual moisture data for the freeze-dried cake and vapor pressure moisture determinations in the space above the freeze-dried cake in the final container. Vapor pressure moisture precision data is presented for α-interferon and BCG vaccine. Impact of residual moisture and vapor pressure moisture upon product stability is presented.

A TA Instruments Thermal Analysis System (TG) has been interfaced to the Hewlett Packard 5972 quadrupole mass spectrometer. An OSS-2 variable outlet splitter was plumbed between the TG and the mass spectrometer. This interface allows continuous monitoring of the ion intensities of mass peaksm/e=18 (water) andm/e=44 (carbon dioxide) used to elucidate the TG transitions attributable to residual moisture in freeze-dried biological products. Moisture specifications must be met in order to insure product stability throughout the approved shelf life. TG/MS results are discussed for BCG Vaccine, BCG Live (Intravesical) and U. S. Standard Antihemophilic Factor. Karl Fischer and TG/MS moisture results are compared.

Six patients underwent imaging studies to evaluate complications related to laparoscopic cholecystectomy. In addition, computed tomography (CT) of the abdomen and pelvis was performed on six patients 3-5 days after uncomplicated laparoscopic cholecystectomy in order to further clarify the normal postoperative CT appearance in these patients. Complications included ureteral laceration with periureteric hematoma and ureteroperitoneal fistula, hepatic artery pseudoaneurysm, hepatic laceration, retained common bile duct stone, bile leak, and biloma of the abdominal wall. At 3-5 days following uncomplicated laparoscopic cholecystectomy, typical CT findings include fluid density in the gallbladder fossa, a very small amount of pelvic fluid, and small densities within the subcutaneous fat at the expected sites of trocar insertion.

Evidence is presented that the pR bat gene is essential for plasmid replication and for spontaneous induction of the SOS response in Escherichia coli. Mutations preventing single-stranded DNA production, needed for pR plasmid replication, also prevent the induction of the SOS system. The following experimental design was used. Firstly, we identified the minima rep region, defined as the minimal DNA sequence necessary for pR plasmid replication and, secondly, analyzed the nucleotide sequence of this region. This identified structures and functions (ori-plus, ori-minus and Rep protein) homologous to those found in phages and plasmids replicating by the rolling-circle mechanism. Finally, mutations were introduced either in the replication protein catalytic site or in the nick site consensus sequence, which caused the pR plasmid to lose its ability to induce the SOS system. We conclude that, in this system, the in vivo SOS-inducing signal appears to be the single-stranded DNA produced during pR replication.

Most emissions of nitrous oxide from semi-arid, temperate grasslands usually occur during the spring thaw. The effects that grazing has on plant litter and snow cover dramatically reduce these seasonal emissions.