5 research outputs found
Palladium-Catalyzed Desulfitative Conjugate Addition of Aryl Sulfinic Acids and Direct ESI-MS for Mechanistic Studies
A new and efficient method for palladiumÂ(II) catalytic
desulfitative
conjugate addition of arylsulfinic acids with α,β-unsaturated
carbonyl compound has been developed. The key reacting intermediates
including aryl PdÂ(II) sulfinic intermediate, aryl PdÂ(II), and Cî—»Oî—¸Pd
complexes were captured by ESI-MS/MS, which provide new experimental
evidence for the understanding of addition mechanism
Table_1_Case report: Plasma cell leukemia secondary to multiple myeloma successfully treated with anti-BCMA CAR-T cell therapy.docx
Chimeric antigen receptor (CAR)-T cell therapy provides an effective salvage treatment for relapsed/refractory multiple myeloma (RRMM) patients. End-stage RRMM with plasma cell leukemia (PCL) transformation is highly aggressive and resistant to conventional therapy. There is an urgent need for new therapeutics and CAR-T therapy may play an important role. We report a case of PCL secondary to RRMM successfully treated with CAR-T cell therapy targeting B-cell maturation antigen (BCMA). A woman was diagnosed as having MM 4 years ago and progressed to secondary PCL (sPCL) of five prior lines of treatment including proteasome inhibitors, an immunomodulatory agent, cytotoxic drugs, and an anti-CD38 monoclonal antibody. After receiving a BCMA CAR-T therapy, she achieved a stringent complete response that lasted 9 months. Then, the patient irregularly took venetoclax 10 mg per day due to a slightly higher λ FLC concentration, which did not meet the criteria for progression. She maintained a complete response for the following 7 months. In conclusion, BCMA CAR-T therapy may be a promising therapeutic approach in PCL patients. More studies are needed to evaluate the benefit of anti-BCMA CAR-T therapy in PCL patients.Clinical Trial Registration:www.chictr.org.cn, ChiCTR1900024388, Registered 9 July 2019.</p
Size-Dependent Changes in Sea Spray Aerosol Composition and Properties with Different Seawater Conditions
A great deal of uncertainty exists
regarding the chemical diversity
of particles in sea spray aerosol (SSA), as well as the degree of
mixing between inorganic and organic species in individual SSA particles.
Therefore, in this study, single particle analysis was performed on
SSA particles, integrating transmission electron microscopy with energy
dispersive X-ray analysis and scanning transmission X-ray microscopy
with near edge X-ray absorption fine structure spectroscopy, with
a focus on quantifying the relative fractions of different particle
types from 30 nm to 1 μm. SSA particles were produced from seawater
in a unique ocean-atmosphere facility equipped with breaking waves.
Changes to the SSA composition and properties after the addition of
biological (bacteria and phytoplankton) and organic material (ZoBell
growth media) were probed. Submicrometer SSA particles could be separated
into two distinct populations: one with a characteristic sea salt
core composed primarily of NaCl and an organic carbon and Mg<sup>2+</sup> coating (SS-OC), and a second type consisting of organic carbon
(OC) species which are more homogeneously mixed with cations and anions,
but not chloride. SS-OC particles exhibit a wide range of sizes, compositions,
morphologies, and distributions of elements within each particle.
After addition of biological and organic material to the seawater,
a change occurs in particle morphology and crystallization behavior
associated with increasing organic content for SS-OC particles. The
fraction of OC-type particles, which are mainly present below 180
nm, becomes dramatically enhanced with increased biological activity.
These changes with size and seawater composition have important implications
for atmospheric processes such as cloud droplet activation and heterogeneous
reactivity
Transition Metal Associations with Primary Biological Particles in Sea Spray Aerosol Generated in a Wave Channel
In
the ocean, breaking waves generate air bubbles which burst at
the surface and eject sea spray aerosol (SSA), consisting of sea salt,
biogenic organic species, and primary biological aerosol particles
(PBAP). Our overall understanding of atmospheric biological particles
of marine origin remains poor. Here, we perform a control experiment,
using an aerosol time-of-flight mass spectrometer to measure the mass
spectral signatures of individual particles generated by bubbling
a salt solution before and after addition of heterotrophic marine
bacteria. Upon addition of bacteria, an immediate increase occurs
in the fraction of individual particle mass spectra containing magnesium,
organic nitrogen, and phosphate marker ions. These biological signatures
are consistent with 21% of the supermicrometer SSA particles generated
in a previous study using breaking waves in an ocean-atmosphere wave
channel. Interestingly, the wave flume mass spectral signatures also
contain metal ions including silver, iron, and chromium. The nascent
SSA bioparticles produced in the wave channel are hypothesized to
be as follows: (1) whole or fragmented bacterial cells which bioaccumulated
metals and/or (2) bacteria-derived colloids or biofilms which adhered
to the metals. This study highlights the potential for transition
metals, in combination with specific biomarkers, to serve as unique
indicators for the presence of marine PBAP, especially in metal-impacted
coastal regions
Quantification and Characterization of Fine Plastic Particles as Considerable Components in Atmospheric Fine Particles
The negative effects of air pollution, especially fine
particulate
matter (PM2.5, particles with an aerodynamic diameter of
≤2.5 μm), on human health, climate, and ecosystems are
causing significant concern. Nevertheless, little is known about the
contributions of emerging pollutants such as plastic particles to
PM2.5 due to the lack of continuous measurements and characterization
methods for atmospheric plastic particles. Here, we investigated the
levels of fine plastic particles (FPPs) in PM2.5 collected
in urban Shanghai at a 2 h resolution by using a novel versatile aerosol
concentration enrichment system that concentrates ambient aerosols
up to 10-fold. The FPPs were analyzed offline using the combination
of spectroscopic and microscopic techniques that distinguished FPPs
from other carbon-containing particles. The average FPP concentrations
of 5.6 μg/m3 were observed, and the ratio of FPPs
to PM2.5 was 13.2% in this study. The FPP sources were
closely related to anthropogenic activities, which pose a potential
threat to ecosystems and human health. Given the dramatic increase
in plastic production over the past 70 years, this study calls for
better quantification and control of FPP pollution in the atmosphere