Notably, 159 confirmed cases have been reported in 23 other countries beyond China, including Japan, Thailand, Singapore, South Korea, Australia, the USA, Malaysia, and Germany. Because of the ...seriousness of this outbreak, WHO declared it a public health emergency of international concern on Jan 30, 2020, followed by the USA announcing a public health emergency on Jan 31, 2020. ...it is important to understand the lung microenvironment and the map of immune responses against 2019-nCoV infection, which might help to define clinical stages and uncover the pathogenesis of the disease. First-line medical staff and scientists in China have had a leading role in fighting the outbreak of 2019-nCoV-associated pneumonia.
There have been significant advances in our understanding of human autoimmunity that have led to improvements in classification and diagnosis and, most importantly, research advances in new ...therapies. The importance of autoimmunity and the mechanisms that lead to clinical disease were first recognized about 50 years ago following the pioneering studies of Macfarlane Burnett and his Nobel Prize‐winning hypothesis of the ‘forbidden clone’. Such pioneering efforts led to a better understanding not only of autoimmunity, but also of lymphoid cell development, thymic education, apoptosis and deletion of autoreactive cells. Contemporary theories suggest that the development of an autoimmune disease requires a genetic predisposition and environmental factors that trigger the immune pathways that lead, ultimately, to tissue destruction. Despite extensive research, there are no genetic tools that can be used clinically to predict the risk of autoimmune disease. Indeed, the concordance of autoimmune disease in identical twins is 12–67%, highlighting not only a role for environmental factors, but also the potential importance of stochastic or epigenetic phenomena. On the other hand, the identification of cytokines and chemokines, and their cognate receptors, has led to novel therapies that block pathological inflammatory responses within the target organ and have greatly improved the therapeutic effect in patients with autoimmune disease, particularly rheumatoid arthritis. Further advances involving the use of multiplex platforms for diagnosis and identification of new therapeutic agents should lead to major breakthroughs within the next decade.
Single-molecule magnets (SMMs) containing only one metal center may represent the lower size limit for molecule-based magnetic information storage materials. Their current drawback is that all SMMs ...require liquid-helium cooling to show magnetic memory effects. We now report a chemical strategy to access the dysprosium metallocene cation (Cp
)Dy(Cp*)
(Cp
, penta-iso-propylcyclopentadienyl; Cp
pentamethylcyclopentadienyl), which displays magnetic hysteresis above liquid-nitrogen temperatures. An effective energy barrier to reversal of the magnetization of
= 1541 wave number is also measured. The magnetic blocking temperature of
= 80 kelvin for this cation overcomes an essential barrier toward the development of nanomagnet devices that function at practical temperatures.
Since early January 2020, after the outbreak of coronavirus infection in Wuhan, China, ≈365 confirmed cases have been reported in Shenzhen, China. The mode of community and intrafamily transmission ...is threatening residents in Shenzhen. Strategies to strengthen prevention and interruption of these transmissions should be urgently addressed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Pyridinium salts are valuable building blocks, which have been widely applied in various organic transformations during the past few decades. In particular, N-functionalized pyridinium salts have ...been explored as convenient radical precursors, which would go through reductive single-electron transfer. As a result, the chemistry of such pyridinium compounds for generating carbon-, nitrogen-, and oxygen-centered radicals has been witnessed, and a remarkable progress has been achieved, making it a hot topic over the last five years. This Review describes recent advances in the area of pyridinium salts as radical precursors, concerning the development of radical reactions involving pyridinium salts in organic synthesis.
An outbreak of coronavirus disease 2019 (COVID-19)
, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
, has spread globally. Countermeasures are needed to treat and prevent ...further dissemination of the virus. Here we report the isolation of two specific human monoclonal antibodies (termed CA1 and CB6) from a patient convalescing from COVID-19. CA1 and CB6 demonstrated potent SARS-CoV-2-specific neutralization activity in vitro. In addition, CB6 inhibited infection with SARS-CoV-2 in rhesus monkeys in both prophylactic and treatment settings. We also performed structural studies, which revealed that CB6 recognizes an epitope that overlaps with angiotensin-converting enzyme 2 (ACE2)-binding sites in the SARS-CoV-2 receptor-binding domain, and thereby interferes with virus-receptor interactions by both steric hindrance and direct competition for interface residues. Our results suggest that CB6 deserves further study as a candidate for translation to the clinic.
ion of a chloride ligand from the dysprosium metallocene (Cpttt)2DyCl (1Dy Cpttt=1,2,4‐tri(tert‐butyl)cyclopentadienide) by the triethylsilylium cation produces the first base‐free rare‐earth ...metallocenium cation (Cpttt)2Dy+ (2Dy) as a salt of the non‐coordinating B(C6F5)4− anion. Magnetic measurements reveal that 2DyB(C6F5)4 is an SMM with a record anisotropy barrier up to 1277 cm−1 (1837 K) in zero field and a record magnetic blocking temperature of 60 K, including hysteresis with coercivity. The exceptional magnetic axiality of 2Dy is further highlighted by computational studies, which reveal this system to be the first lanthanide SMM in which all low‐lying Kramers doublets correspond to a well‐defined MJ value, with no significant mixing even in the higher doublets.
SMMashing: A dysprosium(III) metallocenium cation is a single‐molecule magnet (SMM) with a record anisotropy barrier of 1277 cm−1 and record magnetic blocking up to 60 K, including hysteresis with coercivity.
Very recently, the LHCb collaboration has observed in the final state
Λ
c
+
K
-
π
+
π
+
a resonant structure that is identified as the doubly charmed baryon
Ξ
cc
+
+
. Inspired by this observation, ...we investigate the weak decays of doubly heavy baryons
Ξ
cc
+
+
,
Ξ
cc
+
,
Ω
cc
+
,
Ξ
bc
(
′
)
+
,
Ξ
bc
(
′
)
0
,
Ω
bc
(
′
)
0
,
Ξ
bb
0
,
Ξ
bb
-
and
Ω
bb
-
and focus on the decays into spin 1 / 2 baryons in this paper. At the quark level these decay processes are induced by the
c
→
d
/
s
or
b
→
u
/
c
transitions, and the two spectator quarks can be viewed as a scalar or axial vector diquark. We first derive the hadronic form factors for these transitions in the light-front approach and then apply them to predict the partial widths for the semileptonic and nonleptonic decays of doubly heavy baryons. We find that the number of decay channels is sizable and can be examined in future measurements at experimental facilities like LHC, Belle II and CEPC.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We report a new method to promote the conductivities of metal–organic frameworks (MOFs) by 5 to 7 magnitudes, thus their potential in electrochemical applications can be fully revealed. This method ...combines the polarity and porosity advantages of MOFs with the conductive feature of conductive polymers, in this case, polypyrrole (ppy), to construct ppy‐MOF compartments for the confinement of sulfur in Li–S batteries. The performances of these ppy‐S‐in‐MOF electrodes exceed those of their MOF and ppy counterparts, especially at high charge–discharge rates. For the first time, the critical role of ion diffusion to the high rate performance was elucidated by comparing ppy‐MOF compartments with different pore geometries. The ppy‐S‐in‐PCN‐224 electrode with cross‐linked pores and tunnels stood out, with a high capacity of 670 and 440 mAh g−1 at 10.0 C after 200 and 1000 cycles, respectively, representing a new benchmark for long‐cycle performance at high rate in Li–S batteries.
MOF host S: The electrical conductivity of metal–organic frameworks (MOFs) was promoted by the construction of polymer–MOF composites. Using MOF‐based sulfur hosts, the critical role of porosity at high charge–discharge rates in Li–S batteries was elucidated. MOFs with short ion transfer pathways and large pore apertures were identified as the most suitable for long‐term cycling at extremely high rates.
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