A mixed method assessment of research productivity on microplastics in various compartments in the environment.

Microplastic distribution and pollution as emerging contaminants have become a leading environmental issue globally, owing to their ecological and health implications on biota and humans. Although several bibliometric studies have been reported on microplastics, they are mostly restricted to selected environmental media. As a result, the present study aimed at assessing the literature growth trend of microplastics-related research and their distribution in the environment using a bibliometric approach. The Web of Science Core Collection was explored to retrieve published articles on microplastics from 2006 to 2021, and the data were analysed using the Biblioshiny package of RStudio. This study also highlighted filtration, separation, coagulation, membrane technology, flotation, bionanomaterials, bubble barrier devices, and sedimentation as MP remediation techniques. In the present study, a total of 1118 documents were collected from the literature search; the documents/author and authors/document were 0.308 and 3.25, respectively. A significant growth rate of 65.36% was recorded with notable progress between 2018 and 2021. China, the USA, Germany, the UK, and Italy recorded the highest number of publications within the period under consideration. A collaboration index of 3.32 was also relatively high, with the Netherlands, Malaysia, Iran, France, and Mexico having the highest MCP ratios, respectively. It is anticipated that findings from this study will help the policymakers in addressing issues concerning microplastic pollution assist the researchers in identifying areas to concentrate their studies, and where to seek collaboration in their future research plans. Supplementary Information: The online version contains supplementary material available at 10.1007/s13762-023-04916-7.

Multiplate and TEG platelet mapping in a population of severely injured trauma patients.

OBJECTIVES: The objectives of this study were to compare thromboelastography platelet mapping (TEG PM) with impedance aggregometry (Multiplate, MP) in a single trauma population and relate their results clinically. BACKGROUND: Platelet function as measured by thromboelastography and impedance aggregometry demonstrates significant reductions that persist for days following traumatic injury. However, no study compares these devices and the correlation between them is not known. METHODS: In level 1 trauma patients, TEG PM and MP were conducted at their initial presentation to the emergency department. Within-device repeatability and between-device association were determined using correlation analyses. Demographic variables, Injury Severity Score, blood product transfusion, laboratory test results and mortality rate were recorded. RESULTS: Ninety-two patients were enrolled. Within-device repeatability was high for TEG PM and MP for arachidonic acid (AA) and adenosine diphosphate (ADP) activation pathways. When comparing TEG PM with MP, results correlated poorly in the ADP pathway (Spearman's rho = 0·11, P = 0·44) and moderately in the AA pathway (Spearman's rho = 0·56, P < 0·0001). TEG PM was predictive of blood product transfusion and correlated with increased base deficit, whereas MP was only predictive of mortality. CONCLUSIONS: Intra-device variability was low for TEG PM and MP, but the two point-of-care devices measuring platelet function correlate poorly with each other in injured trauma patients. Each device also had different clinical associations.

Can we use photography to estimate radiation interception by a crop canopy?

Accuracy of determining radiation interception, and hence radiation use efficiency, depends on the method of measuring photosynthetically active radiation intercepted. Methods vary, from expensive instruments such as Sunfleck ceptometers to simple methods such as digital photography. However, before universal use of digital photography there is need to determine its reliability and compare it with conventional, but expensive, methods. In a series of experiments at Lincoln, New Zealand, canopy development for barley, wheat, white clover and four forage brassica species was determined using both digital photographs and Sunfleck ceptometer. Values obtained were used to calculate conversion coefficient (Kf/Ki) ratios between the two methods. Digital photographs were taken at 45° and 90° for barley, wheat and white clover and at only 90° for brassicas. There was an interaction of effects of crop and cultivar for the cereal crops. Barley closed canopies earlier than wheat, and 'Emir' barley and 'Stettler' wheat had consistently higher canopy cover than 'Golden Promise' and 'HY459', respectively. Canopy cover was consistently larger at 45° than 90° for cereals. However, for white clover, the angle of digital photography was not important. There was also an interaction between effects of species and method of determining canopy cover for brassicas. Photographs gave higher cover values than ceptometer for forage rape and turnip, but the relationship was variable for forage kale and swede. Kf/Ki ratios of 1.0-1.10 for cereals, white clover and forage rape and turnip show that digital photographs can be used to estimated radiation interception, in place of Sunfleck ceptometer, for these crops.

X-ray diffuse scattering measurements of nucleation dynamics at femtosecond resolution.

Femtosecond time-resolved small and wide angle x-ray diffuse scattering techniques are applied to investigate the ultrafast nucleation processes that occur during the ablation process in semiconducting materials. Following intense optical excitation, a transient liquid state of high compressibility characterized by large-amplitude density fluctuations is observed and the buildup of these fluctuations is measured in real time. Small-angle scattering measurements reveal snapshots of the spontaneous nucleation of nanoscale voids within a metastable liquid and support theoretical predictions of the ablation process.

Ultrafast bond softening in bismuth: mapping a solid's interatomic potential with X-rays.

Intense femtosecond laser excitation can produce transient states of matter that would otherwise be inaccessible to laboratory investigation. At high excitation densities, the interatomic forces that bind solids and determine many of their properties can be substantially altered. Here, we present the detailed mapping of the carrier density-dependent interatomic potential of bismuth approaching a solid-solid phase transition. Our experiments combine stroboscopic techniques that use a high-brightness linear electron accelerator-based x-ray source with pulse-by-pulse timing reconstruction for femtosecond resolution, allowing quantitative characterization of the interatomic potential energy surface of the highly excited solid.

The site of action of epidurally administered opioids and its relevance to postoperative pain management.

The use of epidurally administered opioids to control postoperative pain is a well established and widely accepted technique. However, despite this longstanding use, there is still an ongoing debate concerning the site of action of the opioids used. Some argue that analgesia is mediated by a spinal mechanism and others that a supraspinal mechanism is responsible. On close inspection of the evidence it becomes apparent that epidural opioids act predominantly spinally when administered as a bolus, and predominantly supraspinally when administered as a continuous infusion. A concentration of 10 microg x ml(-1) appears to be the threshold at which epidurally administered fentanyl can elicit segmental analgesia, a value which may have significant clinical applications. The evidence supporting a synergistic relationship between epidural opioids and local anaesthetics is weak and unsupported by a plausible physiological mechanism. Thus the 'threshold concentration' of approximately 10 microg x ml(-1) is unlikely to be lowered by co-administering opioids with local anaesthetics.

Structure of the molybdenum site of Rhodobacter sphaeroides biotin sulfoxide reductase.

Conditions for heterologous expression of Rhodobacter sphaeroides biotin sulfoxide reductase in Escherichia coli were modified, resulting in a significant improvement in the yield of recombinant enzyme and enabling structural studies of the molybdenum center. Quantitation of the guanine and the molybdenum as compared to that found in R. sphaeroides DMSO reductase demonstrated the presence of the bis(MGD)molybdenum cofactor. UV-visible absorption spectra were obtained for the oxidized, NADPH-reduced, and dithionite-reduced enzyme. EPR spectra were obtained for the Mo(V) state of the enzyme. X-ray absorption spectroscopy at the molybdenum K-edge has been used to probe the molybdenum coordination of the enzyme. The molybdenum site of the oxidized protein possesses a Mo(VI) mono-oxo site (Mo=O at 1.70 A) with additional coordination by approximately four thiolate ligands at 2.41 A and probably one oxygen or nitrogen at 1.95 A. The NADPH- and dithionite-reduced Mo(IV) forms of the enzyme are des-oxo molybdenum sites with approximately four thiolates at 2.33 A and two different Mo-O/N ligands at 2.19 and 1.94 A.

Reduction and coordination of arsenic in Indian mustard.

The bioaccumulation of arsenic by plants may provide a means of removing this element from contaminated soils and waters. However, to optimize this process it is important to understand the biological mechanisms involved. Using a combination of techniques, including x-ray absorption spectroscopy, we have established the biochemical fate of arsenic taken up by Indian mustard (Brassica juncea). After arsenate uptake by the roots, possibly via the phosphate transport mechanism, a small fraction is exported to the shoot via the xylem as the oxyanions arsenate and arsenite. Once in the shoot, the arsenic is stored as an As(III)-tris-thiolate complex. The majority of the arsenic remains in the roots as an As(III)-tris-thiolate complex, which is indistinguishable from that found in the shoots and from As(III)-tris-glutathione. The thiolate donors are thus probably either glutathione or phytochelatins. The addition of the dithiol arsenic chelator dimercaptosuccinate to the hydroponic culture medium caused a 5-fold-increased arsenic level in the leaves, although the total arsenic accumulation was only marginally increased. This suggests that the addition of dimercaptosuccinate to arsenic-contaminated soils may provide a way to promote arsenic bioaccumulation in plant shoots, a process that will be essential for the development of an efficient phytoremediation strategy for this element.

XAS-Collect: a computer program for X-ray absorption spectroscopic data acquisition.

A computer program for X-ray absorption spectroscopy (XAS) data acquisition, called XAS-Collect, is described. The software employs the X Windows system to provide a pull-down menu, dialog-box style of graphical user interface. The software provides state-of-the-art features while still being sufficiently simple for novice users.

Identifying left lower lobe pneumonia at chest radiography: performance of family practice residents before and after a didactic session.

RATIONALE AND OBJECTIVES: The authors sought to determine whether the lateral chest radiograph is helpful in identifying left lower lobe pneumonia among inexperienced readers. MATERIALS AND METHODS: The authors selected all patients who presented to a family practice training program with radiologic and clinical evidence of left lower lobe pneumonia (n = 65). They then selected an equal number of patients in whom chest radiographs were taken to "rule out pneumonia" and were found to be normal. Eight 1st-year family practice residents were asked to read the radiographs before and after a didactic session that emphasized lateral chest radiograph interpretation. The radiographs were presented under two viewing conditions: posteroanterior (PA) only versus PA and lateral. Receiver operating characteristic (ROC) curve methods were used to compare the effect of both the didactic session and the viewing condition on diagnostic accuracy. RESULTS: There were no significant differences in performance before and after the didactic session and no differences between the two viewing conditions. After including only abnormal radiographs that demonstrated the "spine sign" (an apparent increased opacification of the lower vertebral bodies on the lateral view), the residents performed better when presented with both PA and lateral radiographs than when presented with the PA radiograph only (area under ROC curve, .8158 vs .7418, respectively; P = 0.24). CONCLUSION: In patients with left lower lobe pneumonia whose radiographs demonstrated the spine sign, diagnostic accuracy improved when the lateral chest radiograph was viewed.

The independent role of cytomegalovirus as a risk factor for invasive fungal disease in orthotopic liver transplant recipients. Boston Center for Liver Transplantation CMVIG-Study Group. Cytogam, MedImmune, Inc. Gaithersburg, Maryland.

PURPOSE: To assess impact of cytomegalovirus (CMV) donor-recipient serostatus, infection, or disease on development of invasive fungal infection in orthotopic liver transplant recipients. PATIENTS AND METHODS: An analysis of prospectively collected data in 146 liver transplant recipients (intention to treat cohort) from 4 tertiary care, university-affiliated transplant centers in Boston (Boston Center for Liver Transplantation). Patients were observed for 1 year after transplantation for the development of CMV infection, CMV disease, CMV pneumonia, as well as for the development of opportunistic fungal infections, graft survival, and mortality. Weekly cultures were taken of urine and throat and every other week of buffy coat for CMV for 2 months, then monthly for 6 months, at 1 year, and at the time of any clinical illness. Pre- and posttransplant variables including CMV-serostatus of donor and recipient, fungal isolation from sterile body sites, fungemia, bacteremia, antibiotic use, immunosuppression, treatment for rejection, and volumes of blood products were measured. RESULTS: Survival analysis demonstrated that 36% of patients with CMV disease developed invasive fungal disease within the first year post-transplant compared with 8% of those without CMV disease (P < 0.0001). One-year mortality in patients with invasive fungal disease was 15 of 22 (68%) compared with 23 of 124 (19%) in those without invasive fungal disease (P < 0.001). A multivariable, time-dependent analysis demonstrated that being a CMV-seronegative recipient of a CMV-seropositive donor organ (P < 0.001), having bacteremia (P = 0.001), UNOS (United Network for Organ Sharing) status 4 (need for life support measures) at transplant (P = 0.002), and volume of platelets (P = 0.002) were independently associated with invasive fungal disease. Restriction of cases of invasive fungal disease to those that occurred more than 2 weeks after transplant demonstrated an association with CMV disease (P = 0.003), bacteremia (P = 0.003), need for life support (P = 0.03), and volume of blood products transfused (P = 0.02). CONCLUSION: CMV disease or being a CMV-seronegative recipient of a CMV-seropositive donor organ is an important predictor for invasive fungal disease following orthotopic liver transplantation.

Recurrent bacterial peritonitis caused by Neisseria cinerea in a chronic ambulatory peritoneal dialysis (CAPD) patient.

We present an unusual case of recurrent (chronic ambulatory peritoneal dialysis) CAPD-associated peritonitis caused by Neisseria cinerea. Using DNA restriction fragment length polymorphism (RFLP) analysis, we determined that the recurrent infection was caused by reinfection with a different N. cinerea strain rather than relapse with the index strain and that the probable origin of the reinfecting organism was the patient's upper respiratory tract.

Incidence and predictors of cytomegalovirus pneumonia in orthotopic liver transplant recipients. Boston Center for Liver Transplantation CMVIG Study Group.

The incidence, predictors, and outcome of cytomegalovirus pneumonia in OLT recipients have not been well defined. We conducted an analysis of prospectively collected data from 141 OLT recipients who were included as part of a randomized, placebo-controlled trial of CMV immune globulin prophylaxis. Cytomegalovirus pneumonia was diagnosed in 13 of 141 (9.2%) OLT recipients during the first year posttransplant and was associated with a higher 1-year mortality compared with those recipients without CMV pneumonia (84.6 vs. 17.2%, P=0.0001). Univariate analysis demonstrated that CMV viremia (P=0.001), invasive fungal disease (P=0.0001), donor(+)/pretransplant recipient(-) CMV serologic status (P=0.013), abdominal operation (excluding retransplantation) after liver transplantation (P=0.0027), bacteremia (P=0.0105), and advanced United Network of Organ Sharing status (P=0.023) were associated with CMV pneumonia. Cytomegalovirus viremia was diagnosed in 11 of 13 patients with CMV pneumonia at a median of 11 days (range 1-66 days) before diagnosis of CMV pneumonia. In a multivariate analysis using a time-dependent, Cox proportional hazards model, CMV viremia (RR=8.6, 95% CI 1.8-39.7, P=0.0012), invasive fungal disease (RR=6.5, 95% CI 2.1-20.3, P=0.0001), and abdominal reoperation (RR=4.4, 95% CI 1.4-13.1, P=0.0043) were found to be independent predictors of CMV pneumonia. The attributable mortality associated with CMV pneumonia within the first year after liver transplantation for the patients with CMV pneumonia was 67.4%. Intensified measures for prevention of CMV should be considered for patients at high risk of developing CMV pneumonia.

Regulation of calcium-activated potassium channels by S-nitrosothiol compounds and cyclic guanosine monophosphate in rabbit coronary artery myocytes.

BACKGROUND: The patch-clamp technique was used to study a large conductance, calcium-activated potassium channel (IK(Ca) in coronary arterial smooth muscle cells from rabbits. The properties of this channel are similar to those of IK(Ca) found in many types of vascular tissue. A brief single channel characterization of IK(Ca) in this tissue type has been completed for this study. METHODS: The effects of S-nitrosothiol compounds on IK(Ca) were studied in cell-attached patches. RESULTS: The probability of opening for IK(Ca) increased from 0.008 +/- 0.004 to 0.780 +/- 0.07 following application of S-nitroso-L-cysteine. S-nitroso-N-acetylpenicillamine (SNAP) also increased the probability of opening for IK(Ca) from 0.022 +/- 0.01 to 0.601 +/- 0.05. The probability of opening for IK(Ca) also increased from 0.026 +/- 0.01 to 0.809 +/- 0.02 following application of membrane-permeable analogs of cyclic guanosine monophosphate (cGMP) to the bath of cell-attached patches, suggesting that IK(Ca) in coronary artery smooth muscle cells is regulated by a cGMP-dependent mechanism. Rp-8-pCPT-cGMP, a protein kinase G inhibitor, blocked the effect of SNAP, an S-nitrosothiol compound. CONCLUSIONS: These findings suggest that one of the effects of nitrosothiol compounds is the activation of IK(Ca) through a cGMP-dependent mechanism in coronary artery smooth muscle cells.

Clinical evaluation and temperature monitoring in predicting viability in replantations.

Experiences with temperature and clinical monitoring in a series of 111 patients with 188 revascularized digits were reviewed. Criteria for abnormal temperature monitoring were defined. Monitoring of only clinical parameters showed a sensitivity of 1.00 and specificity of .97, but this technique was time-consuming and required experienced interpretation of subtle clinical changes. Temperature monitoring gave a sensitivity of 1.00, while the specificity was only .61. Drops in temperature were frequently not associated with vascular problems. Review of digits with abnormal clinical or temperature monitoring showed five patterns of abnormality. The first three groups had either abnormal clinical or temperature monitoring, but all fingers survived without reexploration. The fourth and fifth groups showed abnormalities in both clinical and temperature monitoring; all but one finger were found to be nonviable. Combined clinical and temperature monitoring was highly effective in early prediction of vascular compromise, with a sensitivity of 1.00 and a specificity of .99. The authors recommend the use of temperature monitoring. If a temperature drop occurs, monitoring of the clinical parameters can then be done. If both temperature and clinical monitoring yield abnormal results after a specified time, intervention should be carried out.

The present and future of hematopoietic cytokines in clinical practice.

Hematologic toxicities can be a major problem in the delivery of some chemotherapy regimens. The way clinicians manage myelosuppression has evolved from a symptomatic approach to the use of cytokines to ameliorate or prevent anemia and neutropenia. Soon, new cytokines will be commercially available to manage thrombocytopenia. Cytokines are transforming oncology by permitting dose intensification through delivery of chemotherapy at the full dose and on time, as well as permitting high-dose chemotherapy. Clinical trials are also exploring the benefits of cytokines for myeloablative chemotherapy with cellular support (bone marrow transplantation or peripheral blood progenitor cell transplantation). Future applications of cytokines include ex vivo expansion and gene transfer therapy. For cancer patients, the ability to receive intensive doses of chemotherapy might mean improved survival rates.

Modification of receptive fields of posteriomedial barrel subfield neocortical single units by known concentrations of iontophoresed noradrenaline in the rat.

Using quantitative electromechanical stimulation of vibrissae poststimulus time histograms were used to map the receptive fields of single units from laminae II/III (12 units), IV (24 units) and V (12 units) of the posteriomedial barrel subfield in urethane anaesthetized rats prior to, and during the iontophoresis of known concentrations of Noradrenaline. All units had multivibrissae receptive fields prior to noradrenaline iontophoresis with laminae II/III units having the smallest size of center and surround receptive field and laminae V the largest. Lamina IV showed the strongest center receptive field response probability magnitude (spikes/stimulus) and the shortest modal latency of evoked responses. Noradrenaline iontophoresis diminished the size of surround receptive fields in each lamina and additionally decreased the size of center receptive fields in laminae IV and V. In Lamina IV, in contrast to laminae II/III and V, response probability magnitude from center receptive field vibrissae was not significantly depressed whilst modal latency of the evoked response was significantly reduced.