1,832 research outputs found
Extensive reuse of soda-lime waste glass in fly ash-based geopolymers
The possibility of extensive incorporation of soda-lime waste glass in the synthesis of fly ash-based geopolymers was investigated. Using waste glass as silica supplier avoids the use of water glass solution as chemical activator. The influence of the addition of waste glass on the microstructure and strength of fly ash-based geopolymers was studied through microstructural and mechanical characterization. Leaching analyses were also carried out. The samples were developed changing the SiO2/Al2O3 molar ratio and the molarity of the sodium hydroxide solution used as alkaline activator. The results suggest that increasing the amount of waste glass as well as increasing the molarity of the solution lead to the formation of zeolite crystalline phases and an improvement of the mechanical strength. Leaching results confirmed that the new geopolymers have the capability to immobilize heavy metal ions
Peptide selfâassembled nanostructures: from models to therapeutic peptides
: Self-assembly is the most suitable approach to obtaining peptide-based materials on the nano- and mesoscopic scales. Applications span from peptide drugs for personalized therapy to light harvesting and electron conductive media for solar energy production and bioelectronics, respectively. In this study, we will discuss the self-assembly of selected model and bioactive peptides, in particular reviewing our recent work on the formation of peptide architectures of nano- and mesoscopic size in solution and on solid substrates. The hierarchical and cooperative characters of peptide self-assembly will be highlighted, focusing on the structural and dynamical properties of the peptide building blocks and on the nature of the intermolecular interactions driving the aggregation phenomena in a given environment. These results will pave the way for the understanding of the still-debated mechanism of action of an antimicrobial peptide (trichogin GA IV) and the pharmacokinetic properties of a peptide drug (semaglutide) currently in use for the therapy of type-II diabetes
National Petroleum Reserve â Alaska (NPR-A) Watershed Hydrology
During a five-year period, which represents the entire project span, the research team performed
discharge measurements on seven gaging stations distributed on the National Petroleum Reserve-
Alaska (NPR-A), an area of approximately 23 million acres that extends from the north side of
the Brooks Range to the Arctic Ocean. Specifically, 225 discharge measurements were taken
during that period. In addition, records of air temperature and rainfall, as well as wind speed and
wind direction from stations that collected such data were analyzed. The air temperature data
indicate that the entire region followed a pronounced warming trend, ending with the 2010/2011
winter, which was the warmest winter recorded at the stations. Rainfall data suggest a trend in
increasing precipitation during the summer months from the coastal plain to the foothill area.
Unusually dry conditions were experienced over the entire area in 2007 and in 2011. The overall
highest mean wind speed was recorded in June at the two stations where wind data were
available; the lowest mean wind speed was recorded in December at one station and in March at
the other station. Wind roses indicate two main wind directionsâroughly from the northeast and
southwestâwith winds from the northeast predominant.List of Figures ................................................................................................................................ iii
List of Tables ................................................................................................................................. iv
Acknowledgments and Disclaimer ................................................................................................. v
Abstract .......................................................................................................................................... vi
CHAPTER 1 Introduction ........................................................................................................... 1
CHAPTER 2 Discharge Measurements ...................................................................................... 3
2.1 Fieldwork ......................................................................................................................... 3
2.2 Data Analysis ................................................................................................................... 7
CHAPTER 3 Meteorological Data ............................................................................................ 10
3.1 Methodology .................................................................................................................. 11
3.2 Results ............................................................................................................................ 11
3.2.1 Rainfall .................................................................................................................... 11
3.2.2 Air Temperature ...................................................................................................... 15
3.2.3 Wind ........................................................................................................................ 20
CHAPTER 4 Information Technology ...................................................................................... 28
4.1 Aquatic Informatics Aquarius Software ......................................................................... 28
4.2 Telemetry Data Retrieval ............................................................................................... 28
4.3 Near-Real-Time Data Delivery Online .......................................................................... 28
4.4 Information Technology Infrastructure .......................................................................... 30
References ..................................................................................................................................... 31
Appendices .................................................................................................................................... 3
Hydrological and Meteorological Observations on Seven Streams in the National Petroleum ReserveâAlaska (NPRâA)
This report summarizes the hydrological and meteorological data collected from 2003 to 2017 at
7 stations in the National Petroleum ReserveâAlaska. During an 8-year period, from May 2010
to December 2017, a research team from the University of Alaska Fairbanks, Water and
Environmental Research Center, and personnel from the Bureau of Land Management performed
351 discharge measurements and collected and analyzed data on air temperature, rainfall, wind
speed, and wind direction at stations distributed on a southwestânortheast transect from the
foothills of the Brooks Range to the Arctic Ocean. In general, the air temperature data indicate an
evident warming trend for the entire region. Rainfall data suggest a trend in increasing
precipitation during the summer months from the coastal plain to the foothills, though there are
some exceptions. The overall highest mean monthly wind speed was recorded in February; the
overall lowest mean monthly wind speed varied from station to station. Wind roses indicate two
main wind directionsâapproximately from the northeast and southwestâwith winds from the
northeast predominant at the northern stations and winds from the southwest predominant at the
southern stations.List of Figures ................................................................................................................................ iii
List of Tables ................................................................................................................................. iv
Acknowledgments and Disclaimer ................................................................................................. v
Abstract .......................................................................................................................................... vi
CHAPTER 1 Introduction ........................................................................................................... 1
CHAPTER 2 Study Area ............................................................................................................. 2
CHAPTER 3 Discharge Measurements ...................................................................................... 3
3.1 Fieldwork ......................................................................................................................... 3
3.2 Data Processing ................................................................................................................ 9
CHAPTER 4 Meteorological Data ............................................................................................ 11
4.1 Methodology .................................................................................................................. 12
4.2 Results ............................................................................................................................ 12
4.2.1 Rainfall .................................................................................................................... 12
4.2.2 Air Temperature ...................................................................................................... 18
4.2.3 Wind ........................................................................................................................ 24
CHAPTER 5 Data Analysis ...................................................................................................... 37
CHAPTER 6 Conclusions and Recommendations.................................................................... 42
References ..................................................................................................................................... 43
Appendices .................................................................................................................................... 4
Recommended from our members
JAK2-STAT5 signaling: A novel mechanism of resistance to targeted PI3K/mTOR inhibition
A recent article published by Britschgi et al. in Cancer Cell, âJAK2/STAT5 Inhibition Circumvents Resistance to PI3K/mTOR Blockade: A Rationale for Cotargeting These Pathways in Metastatic Breast Cancer,â describes a positive feedback loop of JAK2/STAT5 activation that drives resistance to PI3K/mTOR inhibition in breast cancer. The authors found that genetic or pharmacological inhibition of JAK2 circumvents resistance to PI3K/mTOR inhibition and go on to show the efficacy of combined PI3K/mTOR and JAK2 inhibition on reducing cancer cell number, tumor growth, and metastasis as well as increasing in vivo survival. These results provide strong support for combination therapy with JAK2/STAT5 and PI3K/mTOR inhibitors in breast cancer. Here we discuss how the article by Britschgi et al. proposes a novel mechanism to explain how breast cancer cells overcome inhibition of a key signaling pathway driving cell proliferation. We also discuss the interplay between activation of the transcription factors STAT5 and STAT3 in breast cancer
Self-perceived Difficulties With Suicidal Patients in A Sample of Italian General Practitioners
BACKGROUND:
Suicidal behaviours are relatively common among primary care patients, but suicide ideation seems to be poorly detected by GPs. The purpose of the present study is to investigate the frequency of issues related to suicidal behaviour in GPs' setting and to inquire the level of difficulties perceived by physicians when dealing with suicidal patients.
METHODS:
A survey on 88 GPs in Rovigo (Italy) has been conducted through the use of a self-administered questionnaire inquiring about suicidal behaviour in patients, personal history and outside professional lives.
RESULTS:
Four out of 5 doctors have encountered at least a case of suicide in their professional career, and 3 out of 4 recorded at least a case of suicide attempt in a working year. The frequency of personal history of suicidal ideation/behaviour was 2.3%. One third of GPs have come into contact with suicides or suicide attempts outside the professional setting. Sixty one per cent of doctors admitted difficulties in exploring suicidal ideation, but tended to ascribe it to a reluctant attitude of patients.
CONCLUSIONS:
The study underscores GPs' need of being helped in the difficult task of recognising suicidal patient
Mixing and localization in random time-periodic quantum circuits of Clifford unitaries
How much do local and time-periodic dynamics resemble a random unitary? In the present work, we address this question by using the Clifford formalism from quantum computation. We analyze a Floquet model with disorder, characterized by a family of local, time-periodic, and random quantum circuits in one spatial dimension. We observe that the evolution operator enjoys an extra symmetry at times that are a half-integer multiple of the period. With this, we prove that after the scrambling time, namely, when any initial perturbation has propagated throughout the system, the evolution operator cannot be distinguished from a (Haar) random unitary when all qubits are measured with Pauli operators. This indistinguishability decreases as time goes on, which is in high contrast to the more studied case of (time-dependent) random circuits. We also prove that the evolution of Pauli operators displays a form of mixing. These results require the dimension of the local subsystem to be large. In the opposite regime, our system displays a novel form of localization, produced by the appearance of effective one-sided walls, which prevent perturbations from crossing the wall in one direction but not the other
Treatment of Severe Post-traumatic Bone Defects With Autologous Stem Cells Loaded on Allogeneic Scaffolds.
Mesenchymal stem cells may differentiate into angiogenic and osteoprogenitor cells. The effectiveness of autologous pluripotent mesenchymal cells for treating bone defects has not been investigated in humans. We present a case series to evaluate the rationale of using nucleated cells from autologous bone marrow aspirates in the treatment of severe bone defects that failed to respond to traditional treatments. Ten adult patients (mean age, 49.6-years-old) with severe bone defects were included in this study. Lower limb bone defects were >or=5 cm3 in size, and upper limb defects .or=2 cm3. Before surgery, patients were tested for antibodies to common pathogens. Treatment consisted of bone allogeneic scaffold enriched with bone marrow nucleated cells harvested from the iliac crest and concentrated using an FDA-approved device. Postsurgery clinical and radiographic follow-up was performed at 1, 3, 6, and 12 months. To assess viability, morphology, and immunophenotype, bone marrow nucleated cells were cultured in vitro, tested for sterility, and assayed for the possible replication of adventitious (contaminating) viruses. In 9 of 10 patients, both clinical and radiographic healing of the bone defect along with bone graft integration were observed (mean time, 5.6 months); one patient failed to respond. No post-operative complications were observed. Bone marrow nucleated cells were enriched 4.49-fold by a single concentration step, and these enriched cells were free of microbial contamination. The immunophenotype of adherent cells was compatible with that of mesenchymal stem cells. We detected the replication of Epstein-Barr virus in 2/10 bone marrow cell cultures tested. Hepatitis B virus, cytomegalovirus, parvovirus B19, and endogenous retrovirus HERV-K replication were not detected. Overall, 470 to 1,150 million nucleated cells were grafted into each patient. This case series, with a mean follow-up of almost 2 years, demonstrates that an allogeneic bone scaffold enriched with concentrated autologous bone marrow cells obtained from the iliac crest provides orthopedic surgeons a novel option for treating important bone defects that are unresponsive to traditional therapies
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