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Nguyen Van An,1,* Le Huy Hoang,2,* Hai Ha Long Le,3,4 Nguyen Thai Son,1 Le Thu Hong,1 Tien Tran Viet,5 Tuan Dinh Le,6 Ta Ba Thang,7 Luong Huy Vu,8,9 Vinh Thi Ha Nguyen,9,10 Kien Xuan Nguyen11 1Department of Microbiology, Military Hospital 103, Vietnam Military Medical University, Hanoi, Vietnam; 2Department of Bacteriology, National of Hygiene and Epidemiology, Hanoi, Vietnam; 3Department of Microbiology, Mycology and Parasitology, National hospital of Dermatology and Venereology, Hanoi, Vietnam; 4Department of Clinical Microbiology and Parasitology, Ha Noi Medical University, Hanoi, Vietnam; 5Department of Infectious Diseases, Military Hospital 103, Vietnam Medical Military University, Hanoi, Vietnam; 6Department of Rheumatology and Endocrinology, Military Hospital 103, Vietnam Medical Military University, Hanoi, Vietnam; 7Respiratory Center, Military Hospital 103, Vietnam Military Medical University, Hanoi, Vietnam; 8Department of Laser and Skin Care, National hospital of Dermatology and Venereology, Hanoi, Vietnam; 9Department of Dermatology and Venereology, Ha Noi Medical University, Hanoi, Vietnam; 10Department of General Planning, National hospital of Dermatology and Venereology, Hanoi, Vietnam; 11Department of Military Medical Command and Organization, Vietnam Medical Military University, Hanoi, Vietnam*These authors contributed equally to this workCorrespondence: Kien Xuan Nguyen, Department of Military Medical Command and Organization, Vietnam Medical Military University, Hanoi, Vietnam, Email nguyenxuankien@vmmu.edu.vnPurpose: Studies on the epidemiology of bloodstream infection (BSI) and antimicrobial resistance (AMR) are limited in Vietnam. Thus, the present study aimed to elucidate the epidemiology of BSI and AMR of BSI-causing bacteria in Vietnam.Methods: Data regarding blood cultures from 2014 to 2021 were collected and analyzed using the chi-square test, Cochran–Armitage test, and binomial logistic regression model.Results

A well known issue with concordance cosmology is the cosmological lithium problem, where models of Big Bang Nucleosynthesis indicate abundances of 7Li three to four times larger than values inferred via spectroscopic measurements of metal-poor halo stars [1]. Since the source of this discrepancy remains unclear [2], it is vital to fully understand the nuclear reactions that affect the production of 7Li during the Big Bang [3]. At the Australian National University, experimental equipment and analysis techniques have been developed for nuclear reaction studies at energies near the fusion barrier, exploiting large solid angle detectors to enable the investigation of breakup without a priori assumption of the breakup kinematics. The extension to reactions of astrophysical interest may help shed light on these reactions. Recent experiments, using these new techniques, have provided a complete picture of the breakup mechanisms of light nuclei in collisions with heavy targets [4]. The present work focuses on obtaining a complete picture of breakup mechanisms of 7Li following interactions with 27Al. It has been found that breakup is almost exclusively triggered by nucleon transfer between the colliding partners, to a larger extent than was found for heavier targets. The findings of these experiments, as well as progress towards extensions to astrophysically relevant reactions, such as d + 7Be [5] will be presented.

The understanding of quantum effects in determining nuclear reaction outcomes is evolving as improved experimental techniques reveal new facets of interaction dynamics. Whilst the phenomenon of coupling-enhanced quantum tunnelling is understood to arise due to quantum superposition, the observed inhibition of fusion at energies well below the barrier is not yet quantitatively understood. Collisions involving weakly-bound nuclei, which have low energy thresholds against breakup, present further challenges. Recent coincidence measurements for reactions of weakly bound stable nuclei have not only provided a complete picture of the physical mechanisms triggering breakup, but have also shown how information on reaction dynamics occurring on time-scales of ∼zepto-seconds can be obtained experimentally. These new experimental findings demand major developments in quantum models of near-barrier nuclear reactions.

Mass-angle distributions carry detailed information on the characteristics of quasifission, and thus of the dynamics of heavy element formation reactions. Recent experimental results are presented and discussed.

The quasifission mechanism hinders fusion in heavy systems through breakup within zeptoseconds into two fragments with partial mass equilibration. Its dependence on the structure of both the collision partners and the final fragments is a key question. Our original approach is to combine an experimental measurement of the fragments' mass-angle correlations in Ca40+U238 with microscopic quantum calculations. We demonstrate an unexpected interplay between the orientation of the prolate deformed U238 with quantum shell effects in the fragments. In particular, calculations show that only collisions with the tip of U238 produce quasifission fragments in the magic Z=82 region, while collisions with the side are the only ones that may result in fusion.

This contribution presents an overview of the research program in nuclear reaction dynamics at the Australian National University.

Shell effects can play a prominent role in fission fragment mass distributions. For lighter systems in the region of A∼180-200, mass distributions were generally expected to be symmetric. However, a recent experiment showed that fission of 180Hg followi

Coincidence measurements of breakup fragments were carried out for the 7Li + 197Au and 204Pb systems at sub-barrier energies. The mechanisms triggering breakup, and time-scales of each process, were identified through the reaction Q-values and the relativ

A significant challenge to nuclear astrophysics is the cosmological lithium problem, where models of Big Bang nucleosynthesis indicate abundances of 7Li two to four times larger than what is inferred via spectroscopic measurements of metal-poor stars. Rec

The disagreement between observed 7Li abundances in metal-poor halo stars and primordial 7Li abundances predicted in Big Bang Nucleosynthesis (BBN) calculations has presented a challenge to the astrophysics community for some time. The absence of a clear

Mass-angle distributions carry detailed information on the characteristics of quasi-fission, and thus of the dynamics of heavy element formation reactions. Recent experimental results are presented and discussed.

Coincidence measurements of breakup fragments were carried out for the 7Li+144Sm and 6,7Li+207,208Pb,209Bi reactions at sub-barrier energies. Breakup modes in reactions of 6,7Li were identified through the reaction Q values, and the time-scales of each pr

Background: The formation of superheavy elements by fusion of two massive nuclei is severely inhibited by the competing quasifission process. Purpose: Through extensive mass-angle distribution measurements, we map out the systematic dependence of quasifis

Background: Quasifission, a fission-like reaction outcome in which no compound nucleus forms, is an important competitor to fusion in reactions leading to superheavy elements. The precise mechanisms driving the competition between quasifission and fusion

A pair of twin position-sensitive parallel plate avalanche counters have been developed at the Australian National University as a tracking system to aid in the further rejection of unwanted beam particles from a 6.5 T super conducting solenoid separator

Nuclear reaction dynamics at energies near the fusion barrier is known to be dominated by quantum effects, such as tunneling, and quantum superpositions that gives rise to channel couplings. The understanding of near-barrier reaction dynamics continues to

The influence of breakup channels on the complete fusion of weakly bound systems is investigated in terms of dynamic polarization potentials. The systematic enhancement of the cross section at sub-barrier energies seems to be consistent with recent experi

A 6.5 Tesla superconducting gas-filled solenoid (SOLITAIRE) has been developed at the Heavy Ion Accelerator Facility at the ANU as a reaction product separator. Key features of the device allowing its application for precise measurement of heavy ion fusio

The quasi-fission mechanism hinders fusion of heavy systems because of a mass flow between the reactants, leading to a re-separation of more symmetric fragments in the exit channel. A good understanding of the competition between fusion and quasi-fission

A highly efficient superconducting solenoidal fusion product separator has been developed at the Australian National University in order to enable separation and detection of evaporation residues following heavy-ion collisions. The determination of absolu

Using a position sensitive detector array, back-angle coincidence measurements of breakup fragments at sub-barrier energies has enabled the complete characterisation of the breakup processes in the reactions of 6,7Li with 208Pb. Breakup processes and thei