DFT study of water on graphene: Synergistic effect of multilayer p-doping.

Recent experiments related to a study concerning the adsorption of water on graphene have demonstrated the p-doping of graphene, although most of the ab initio calculations predict nearly zero doping. To shed more light on this problem, we have carried out van der Waals density functional theory calculations of water on graphene for both individual water molecules and continuous water layers with coverage ranging from one to eight monolayers. Furthermore, we have paid attention to the influence of the water molecule orientation toward graphene on its doping properties. In this article, we present the results of the band structure and the Bader charge analysis, showing the p-doping of graphene can be synergistically enhanced by putting 4-8 layers of an ice-like water structure on graphene having the water molecules oriented with oxygen atoms toward graphene.

Epidemiology of neonatal sepsis in two neonatal intensive care units in Krakow, Poland in 2016-2017 years.

BACKGROUND: Sepsis in low-birth-weight neonates remains one of the most significant causes of neonatal morbidity and mortality. Approximately 3 million newborns suffer from sepsis globally every year. The aim of this study was to compare demographic and clinical features, as well as etiology and antibiotic susceptibility, of the main pathogens related to neonatal sepsis in two neonatal intensive units during a two-year period. METHODS: We observed early-onset (EO-BSI) and late-onset bloodstream infections (LO-BSI) cases in two high-reference neonatal intensive care units (NICU) over a 24-month period (2016-2017). Samples of patients' blood were tested for the presence of the microorganisms. All bacterial isolates were tested for susceptibility to antibiotics. RESULTS: The majority of sepsis cases weighed above 1000 g and were born by cesarean section. About 10% of the EO-BSI group died. There were differences in the EO-BSI /LO-BSI ratio in the compared wards due to differences among the admitted children. The most common pathogens isolated from blood were coagulase-negative staphylococci (CoNS) were represented by two dominating species: S. epidermidis and S. haemolyticus, followed by Klebsiella spp. strains and E.coli, which were mostly found in EO-BSI cases. No single S. agalactiae (GBS) strain was isolated. The majority of CoNS strains were resistant to methicillin, half were resistant to aminoglycosides, and one-third were resistant to macrolides and lincosamides. Half of the Gram-negative rods were resistant to beta-lactams. CONCLUSIONS: The epidemiology of sepsis in two observed NICUs is comparable to data obtained from other studies with a predominance of methicillin-resistant CoNS in LO-BSI and beta-lactam resistant E. coli in EO-BSI. It is of importance that the campaign for controlling GBS carriage in pregnant women in Poland resulted in the disappearance of GBS as a cause of sepsis. Unfortunately, there are no such measures to control E.coli related sepsis.

Secondary bacterial infections & extensively drug-resistant bacteria among COVID-19 hospitalized patients at the University Hospital in Kraków.

INTRODUCTION: Healthcare-associated infections (HAI) and bacterial antimicrobial resistance posed a therapeutic risk during the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to analyze the HAIs in COVID-19 patients in the Intensive Care Unit (ICU) and non-ICU at the University Hospital in Krakow (UHK) with an emphasis on the susceptibility of the most frequently isolated pathogens and the prevalence of extensively drug resistant (XDR) microorganisms. METHODS: This laboratory-based study was carried out at the University Hospital in Krakow in the ICU and non-ICUs dedicated to COVID-19 patients between May 2021 and January 2022. All isolates of Klebsiella pneumoniae were analyzed using PFGE protocol. RESULTS: 292 independent HAI cases were identified, with the predominance of urinary tract infections (UTI), especially in the non-ICU setting. The most common ICU syndrome was pneumonia (PNA). The prevalence of XDR organisms was 22.6% in the ICU and 14.8% in non-ICUs among all isolates. The incidence of carbapenem-resistant Enterobacteriaceae infection was 24.8 cases per 10,000 hospitalizations and the carbapenem-resistant A. baumannii infection incidence was 208.8 cases per 10,000 hospitalizations. The prevalence of XDR strains was highest in Acinetobacter spp, in PNA cases. The PFGE typing demonstrated that almost all XDR strains varied widely from each other. CONCLUSIONS: In this study, there was a high incidence of HAI in COVID-19 patients, especially when compared to Western Europe and the United States. Similarly, the prevalence of XDR microorganisms, especially XDR-A.baumannii, was also high. PFGE did not confirm the horizontal spread of any organism strains.

Antimicrobial Resistance in Enterobacterales Bacilli Isolated from Bloodstream Infection in Surgical Patients of Polish Hospitals.

BACKGROUND AND AIMS: Bloodstream infections (BSIs) are one of the most frequently observed hospital-acquired infections (HAIs). We sought to describe the epidemiology and drug resistance secondary Enterobacterales BSIs in surgical patients and check for any correlation with the type of hospital ward. MATERIALS AND METHODS: This multicenter (13 hospitals in southern Poland) laboratory-based retrospective study evaluated adults diagnosed with BSI secondary to surgical site infection (SSI) hospitalized in 2015-2018; 121 Enterobacterales strains were collected. The drug resistance was tested according to the EUCAST recommendations. Tests confirming the presence of extended-spectrum ß-lactamases (ESBLs) and bla resistance genes were carried out. The occurrence of possible clonal epidemics among K. pneumoniae strains was examined. RESULTS: The prevalence of Enterobacterales in secondary BSI was 12.1%; the most common strains were E. coli (n = 74, 61.2%) and Klebsiella spp. (n = 33, 27.2%). High resistance involved ampicillin and ampicillin/sulbactam (92, 8-100%), fluoroquinolones (48-73%), and most cephalosporins (29-50%). Carbapenems were the antimicrobials with the susceptibility at 98%. The prevalence of ESBL strains was 37.2% (n = 45). All the ESBL strains had bla CTX-M gene, 26.7% had the bla SHV gene, and 24.4% had bla TEM gene. The diversity of Klebsiella strains was relatively high. Only 4 strains belonged to one clone. CONCLUSIONS: What is particularly worrying is the high prevalence of Enterobacterales in BSI, as well as the high resistance to antimicrobial agents often used in the empirical therapy. To improve the effectiveness of empirical treatment in surgical departments, we need to know the epidemiology of both surgical site infection and BSI, secondary to SSI. We were surprised to note high heterogeneity among K. pneumoniae strains, which was different from our previous experience.

Density functional study of gallium clusters on graphene: electronic doping and diffusion.

Motivated by experimental results on transport properties of graphene covered by gallium atoms, the density functional theory study of clustering of gallium atoms on graphene (up to a size of 8 atoms) is presented. The paper explains a rapid initial increase of graphene electron doping by individual Ga atoms with Ga coverage, which is continually reduced to zero, when bigger multiple-atom clusters have been formed. According to density functional theory calculations with and without the van der Waals correction, gallium atoms start to form a three-dimensional cluster from five and three atoms, respectively. The results also explain an easy diffusion of Ga atoms while forming clusters caused by a small diffusion barrier of 0.11 eV. Moreover, the calculations show this barrier can be additionally reduced by the application of an external electric field, which was simulated by the ionization of graphene. This effect offers a unique possibility to control the cluster size in experiments only by applying a gate-voltage to the graphene in a field-effect transistor geometry and thereby without growth temperature assistance.

Nail microbial colonization following hand disinfection: a qualitative pilot study.

Effective hand hygiene among healthcare workers is one of the basic principles of preventing nosocomial infections. The aim of the study was a qualitative examination of microbial colonization of nails following hand hygiene. The results were stratified by nail length: short versus long and the presence of a varnish coating: natural versus varnished. The presence of potentially pathogenic micro-organisms was correlated with nail length (odds ratio: 7.1; 95% confidence interval: 1.83-27.39; P < 0.001) and the presence of ultraviolet (UV)-cured nail polish (7.2; 1.25-40.91; P < 0.05). There is a high probability of ineffective hand hygiene when keeping long nails and when UV-cured nail polish is present on them.

Regulation of fetal hemoglobin expression during hematopoietic stem cell development and its importance in bone metabolism and osteoporosis.

We have shown that an altered tissue redox environment in mice lacking either murine beta Hemoglobin major (HgbßmaKO) or minor (HgbßmiKO) regulates inflammation. The REDOX environment in marrow stem cell niches also control differentiation pathways. We investigated osteoclastogenesis (OC)/osteoblastogenesis (OB), in bone cultures derived from untreated or FSLE-treated WT, HgbßmaKO or HgbßmiKO mice. Marrow mesenchymal cells from 10d pre-cultures were incubated on an osteogenic matrix for 21d prior to analysis of inflammatory cytokine release into culture supernatants, and relative OC:OB using (TRAP:BSP, RANKL:OPG) mRNA expression ratios and TRAP or Von Kossa staining. Cells from WT and HgbßmaKO mice show decreased IL-1ß,TNFα and IL-6 production and enhanced osteoblastogenesis with altered mRNA expression ratios and increased bone nodules (Von Kossa staining) in vitro after in vivo stimulation of mRNA expression of fetal Hgb genes (Hgbε and Hgbßmi) by a fetal liver extract (FSLE). Marrow from HgbßmiKO showed enhanced cytokine release and preferential enhanced osteoclastogenesis relative to similar cells from WT or HgbßmaKO mice, with no increased osteoblastogenesis after mouse treatment with FSLE. Pre-treatment of WT or HgbßmaKO, but not HgbßmiKO mice, with other molecules (rapamycin; hydroxyurea) which increase expression of fetal Hgb genes also augmented osteoblastogenesis and decreased cytokine production in cells differentiating in vitro. Infusion of rabbit anti- Hgbε or anti- Hgbßmi, but not anti-Hgbα or anti- Hgbßma into WT mice from day 13 gestation for 3 weeks led to attenuated osteoblastogenesis in cultured cells. We conclude that increased fetal hemoglobin expression, or use of agents which improve fetal hemoglobin expression, increases osteoblast bone differentiation in association with decreased inflammatory cytokine release.

Infections following surgical patent ductus arteriosus ligation in very-low-birthweight neonates.

BACKGROUND: Very-low-birthweight (VLBW) neonates (<1500g) comprise approximately 1% of liveborn infants in Poland. Patent ductus arteriosus (PDA) is a common complication of prematurity. This study aimed to determine how many VLBW neonates treated in the participating units needed surgical correction of PDA, and to evaluate the incidence of various types of postoperative infections and their microbiology. METHODS: Observational study in five neonatology departments by the Polish Neonatology Surveillance Network, involving 2039 VLBW newborns of whom 103 (5.1%) required surgical PDA ligation. Continuous infection surveillance was conducted between 2009 and 2013; infections were defined based on Gastmeier's criteria. RESULTS: PDA surgery was required significantly more frequently in infants from multiple pregnancies, and where labour was complicated by amnionitis. Surgical PDA correction was performed, on average, at 19 days of life. The incidence of infection was 48.5% (N = 50), and the most common infections were bloodstream infection (26.2%) and pneumonia (22.3%). A correlation was observed between the day on which the procedure was performed and the time of infection: the earlier the neonate underwent PDA surgery, the earlier the infection manifested (P = 0.032). A high CRIB score and chorioamnionitis contributed significantly to the presence of infection. CONCLUSION: The later the PDA surgery was performed, the later the infection occurred. The incidence of infection after correction of PDA among VLBW neonates was comparable with the incidence of infection among all hospitalized VLBW neonates.

[Recombinant Monoclonal Antibodies, from Tumor Targeting to Cancer Immunotherapy: A Critical Overview].

In view of the explosion of the present clinical use of monoclonal antibodies (mAbs), not only in the treatment of cancer, but also of autoimmune diseases, I was asked to review the development of mAbs in tumor diagnosis and therapy, with some illustrations of our own contribution in the field. The initial use of radiolabeled mAbs for tumor targeting and radioimmunotherapy led to the extensive clinical application of unlabeled, "humanized" mAbs for cancer therapy, which I describe with a critical perspective. The introduction of recombinant bispecific antibodies, capable of bridging T lymphocytes with tumor cells and inducing killing of the cancer cells, was found to be mostly active in the treatment of hematological malignancies. Most interestingly, the use of mAbs not directed to the tumor cells, but to inhibitory receptors expressed by cytotoxic T lymphocytes, which trigger them to kill the cancer cells, represents a new form of active cancer immunotherapy. My motivation in writing this review was related to my long-term interactions with several Russian scientists, mentioned at the end of this article.

Electronic transport properties of graphene doped by gallium.

In this work we present the effect of low dose gallium (Ga) deposition (<4 ML) performed in UHV (10-7 Pa) on the electronic doping and charge carrier scattering in graphene grown by chemical vapor deposition. In situ graphene transport measurements performed with a graphene field-effect transistor structure show that at low Ga coverages a graphene layer tends to be strongly n-doped with an efficiency of 0.64 electrons per one Ga atom, while the further deposition and Ga cluster formation results in removing electrons from graphene (less n-doping). The experimental results are supported by the density functional theory calculations and explained as a consequence of distinct interaction between graphene and Ga atoms in case of individual atoms, layers, or clusters.

An altered REDOX environment, assisted by over-expression of fetal hemoglobins, protects from inflammatory colitis and reduces inflammatory cytokine expression.

C5BL/6 female mice receiving dextran sodium sulfate in their drinking water develop an acute inflammatory colitis within 7d, with weight loss, histopathologic signs of inflammation, and colonic expression of inflammatory cytokines. In previous studies we have reported that increased inflammatory cytokine expression in aged mice can be attenuated by oral gavage of a crude fetal extract containing glutathione (GSH), MPLA and fetal hemoglobin, or more specifically by injection of a combination of these purified reagents. We speculated that this combination led to an altered tissue redox environment in which the immune response developed, thus regulating inflammation. Accordingly, we used wild-type (WT) C57BL/6 mice, or mice lacking either murine beta Hemoglobin major (HgbßmaKO) or minor (HgbßmiKO) as recipients of DSS in their drinking water, and followed development of colitis both clinically and by inflammatory cytokine production, before/after oral treatment of mice with a crude fetal liver extract. Mice lacking an intact fetal hemoglobin chain (HgbßmiKO) developed severe colitis, with enhanced colonic expression of inflammatory cytokines, which could not be rescued by extract, unlike WT and HgbßmaKO animals. Moreover, disease in both WT and HgbßmaKO animals could also be attenuated by exposure to 5-hydroxymethyl furfural (5HMF), hydroxyurea or rapamycin. The former has been used as an alternative means of stabilizing the conformation of adult hemoglobin in a manner which mimicks the oxygen-affinity of fetal hemoglobin, while we show that both hydroxyurea and rapamycin augment expression of murine fetal hemoglobin chains. Our data suggests there may be a clinical value in exploring agents which alter local REDOX environments as an adjunctive treatment for colitis and attenuating inflammatory cytokine production.

Antibiotic consumption in laboratory confirmed vs. non-confirmed bloodstream infections among very low birth weight neonates in Poland.

BACKGROUND: Newborns are a population in which antibiotic consumption is extremely high. Targeted antibiotic therapy should help to reduce antibiotics consumption. The aim of this study was an assessment of antibiotic usage in bloodstream infections treatment in the Polish Neonatology Surveillance Network (PNSN) and determining the possibility of applying this kind of data in infection control, especially for the evaluation of standard methods of microbiological diagnostics. METHODS: Data were collected between 01.01.2009 and 31.12.2013 in five teaching NICUs from the PNSN. The duration of treatment in days (DOT) and the defined daily doses (DDD) were used for the assessment of antibiotics consumption. RESULTS: The median DOT for a single case of BSI amounted to 8.0 days; whereas the median consumption expressed in DDD was 0.130. In the case of laboratory confirmed BSI, median DOT was 8 days, and consumption-0.120 DDD. Median length of therapy was shorter for unconfirmed cases: 7 days, while the consumption of antibiotics was higher-0.140 DDD (p < 0.0001). High consumption of glycopeptides expressed in DOTs was observed in studied population, taking into account etiology of infection. CONCLUSIONS: Even application of classical methods of microbiological diagnostics significantly reduces the consumption of antibiotics expressed by DDD. However, the high consumption of glycopeptides indicates the necessity of applying rapid diagnostic assays. Nevertheless, the assessment of antibiotic consumption in neonatal units represents a methodological challenge and requires the use of different measurement tools.

Molecular analysis of meticillin-resistant Staphylococcus aureus strains isolated from different types of infections from patients hospitalized in 12 regional, non-teaching hospitals in southern Poland.

BACKGROUND: Accumulated data indicate that meticillin-resistant Staphylococcus aureus (MRSA) infections are associated with a worse prognosis than methicillin-susceptible S. aureus infections. AIM: To assess the epidemiological profile of S. aureus infections and the genetic diversity of clinical strains of MRSA in 12 hospitals in southern Poland. METHODS: Samples from bloodstream infections, pneumonia, and skin and soft tissue infections from adult patients were examined. S. aureus isolates were tested for MRSA and macrolide-lincosamide-streptogramin B (MLSB) phenotypes. Staphylococcal cassette chromosome mec (SCCmec) typing and S. aureus protein A (spa) typing were performed. Analysis of the genetic similarity was performed by pulsed-field gel electrophoresis. RESULTS: This study included 555 patients. An MRSA phenotype was detected in 15.1% of strains. The prevalence of MRSA infection was higher in patients aged >80 years. An MLSB phenotype was detected in 18.2% of strains. Analysis of SmaI profiles did not reveal a dominant clone. Spa typing showed 25 different spa types, and spa type t003 was the most common (49% of strains). Among MRSA strains, SCCmecII (49%) and SCCmecIV (27.4%) were predominant. CONCLUSION: The characteristics of MRSA showed considerable heterogeneity. The results demonstrate the need for caution when drawing conclusions on direct epidemiological relationships between isolates based on a single typing method. As the cases of infection in this study were not associated with the hospital environment and horizontal transfer, a focus on screening at hospital admission, and appropriate infection control, may help to reduce the risk of MRSA infections.

Urinary tract infections caused by Pseudomonas aeruginosa among children in Southern Poland: Virulence factors and antibiotic resistance.

OBJECTIVE: The aim of this study was to analyze antibiotic resistance and virulence patterns in Pseudomonas aeruginosa (PAR) isolates from urinary tract infections among children in Southern Poland. MATERIALS AND METHODS: This study comprised consecutive, non-repetitive PAR isolates sent from two collaborative laboratories. The study group consisted of children aged up to 17 years from Southern Poland with culture-proven PAR UTIs. Relevant information about patients with UTIs, such as age, sex, and type of infection (polymicrobial or monomicrobial), was collected. Isolates were screened for major virulence factors found in uropathogenic PAR strains. Multidrug-resistant (MDR) strains were defined as strains not susceptible to one antimicrobial in at least three different antimicrobial classes. Extensively drug resistant (XDR) strains were defined as strains susceptible to no more than two antimicrobial classes. RESULTS: The total prevalence of PAR UTIs was 2.1%, and in children <5 years of age it was 3.0%. A total of 26 isolates was tested: 21 from outpatients and five from inpatients. Most infections (80.8%) occurred in children ≤ 4 years of age. The most prevalent virulence gene was exoY (96.2%). The prevalence of other effector proteins was 88.5% for exoT, 92.3% for exoS, and 19.2% for exoU. The gene for LasB was present in 80.8% of isolates; the gene for AprA in 61.5%; the gene for PilA in 19.2%; and the gene for PilB was not detected. The PAR isolates were generally susceptible to beta-lactam and aminoglycoside antimicrobials. All isolates were also susceptible to colistin. A large proportion of isolates were resistant to carbapenems and fluoroquinolones (Fig. 1). No significant differences were found in antimicrobial resistance between males and females or inpatients and outpatients (p > 0.05 for all tested antimicrobials), or in antimicrobial resistance between younger (≤ 5 years old, n = 21) and older (> 5 years old, n = 5) children (p > 0.05 for all tested antimicrobials). Two isolates were classified as XDR and none as MDR. The EDTA test yielded one MBL-positive isolate (3.8%), from a 17-year-old patient in home care. No isolates with genes for the KPC, IMP, or VIM were identified. CONCLUSION: As data on UTIs in children with Pseudomonas etiology are scarce, this paper provides useful information for clinicians and allows for comparison between Poland and other countries. Our findings have important implications for clinicians treating UTIs empirically, because the success of empiric treatment is based on knowledge of pathogen antimicrobial susceptibility patterns.

Infections and risk-adjusted length of stay and hospital mortality in Polish Neonatology Intensive Care Units.

BACKGROUND: The objectives of this study were to analyze the impact of infections on prolonging hospital stay with consideration of underlying risk factors and determining the mortality rates and its association with infections. METHODS: An electronic database developed from a continuous prospective targeted infection surveillance program was used in the study. Data were collected from 2009 to 2012 in five Polish tertiary academic neonatal intensive care units (NICUs). The length of stay (LOS) of 2,003 very low birth weight (VLBW) neonates was calculated as the sum of the number of days since birth until death or until reaching a weight of 1,800g. RESULTS: The median LOS for neonates with infections was twice as high as for neonates without infection. LOS was significantly affected by the overall general condition of the neonate, as expressed by both gestational age and birth weight as well as by the Clinical Risk Index for Babies (CRIB) score; another independent factor was presence of at least one infection. Risk of in-hospital mortality was significantly increased by male sex and vaginal birth and was lower among breastfed neonates. Deaths were significantly more frequent in neonates without infection. CONCLUSIONS: The general condition of VLBW infants statistically increase both their risk of mortality and LOS; this is in contrast to the presence of infection, which significantly prolonged LOS only.

[Informed consent]. / Informovaný souhlas.

Unless it is necessary to provide immediate assistance to a patient who, due to his state of health, is unable to give consent, every medical treatment must be performed with an voluntary consent from the patient. The patient must be informed, in advance, about the purpose and nature of the treatment, its consequences and risks. If the patient refuses the proposed treatment he must be notified about the possible harmful effects of this decision for his health (life) and the patient must sign a written refusal of the medical treatment - commonly known as revers. In case the patient refuses both the treatment and the signature, then the refusal must be signed by a witness. Informed consent may be oral; its written form is obligatorily dictated by law only in exceptional cases. Every health service provider is solely responsible for deciding which treatments will require written consents. The refusal form, revers, must always be written. The European courts have been emphasising that the most significant thing is the dialogue between the doctor and the patient, not the signed document. The patient must be informed by a relevant doctor about the treatment he is about to undergo not by a nurse or a doctor who will not be performing it. It is questionable whether it would not be better to substitute a written consent for an audio or audio-visual recording showing the interaction between the doctor and the patient, or his family. Anyone is allowed to express a future wish for situations when he will not be able to agree or disagree with the offered health services (that means previously expressed wishes - living will). The law will determine the formalities of such a document. Previously expressed wish should be respected unequivocally, although, its fulfillment must not lead to active cause of death. The rule is that human free will gives way to the protection of his life.