36 research outputs found
Image_2_Case report: Heart failure secondary to myocardial infarction in a fertile woman with woven coronary artery.JPEG
A 42-year-old female was hospitalized with 2-day history of fever, dyspnea, and chest tightness. Four years ago, she had similar symptoms at the eighth week of gestation. Computed tomography coronary angiography only suggested moderate stenosis, but cardiac MRI indicated myocardial infarction. The coronary angiography demonstrated a woven coronary artery. She underwent successful coronary artery bypass grafting surgery and took medication regularly. Finally, the prognosis was favorable. Cardiovascular events seldom happen in fertile women because of the protection of estrogen, but once it occurs, the potential cause, such as coronary anomaly and other risk factors, should not be overlooked.</p
Image_1_Case report: Heart failure secondary to myocardial infarction in a fertile woman with woven coronary artery.JPEG
A 42-year-old female was hospitalized with 2-day history of fever, dyspnea, and chest tightness. Four years ago, she had similar symptoms at the eighth week of gestation. Computed tomography coronary angiography only suggested moderate stenosis, but cardiac MRI indicated myocardial infarction. The coronary angiography demonstrated a woven coronary artery. She underwent successful coronary artery bypass grafting surgery and took medication regularly. Finally, the prognosis was favorable. Cardiovascular events seldom happen in fertile women because of the protection of estrogen, but once it occurs, the potential cause, such as coronary anomaly and other risk factors, should not be overlooked.</p
Table_1_Comparison of cumulative live birth rates between progestin-primed ovarian stimulation protocol and gonadotropin-releasing hormone antagonist protocol in different populations.docx
ObjectiveTo compare cumulative live birth rate (LBR) between progestin-primed ovarian stimulation (PPOS) and GnRH antagonist protocols of preimplantation genetic testing (PGT) cycles in different populations.MethodsThis was a retrospective cohort study. A total of 865 patients were enrolled and separate analyses were performed for three populations: 498 patients with predicted normal ovarian response (NOR), 285 patients with PCOS, and 82 patients with predicted poor ovarian response (POR). The primary outcome was cumulative LBR for one oocyte retrieval cycle. The results of response to ovarian stimulation were also investigated, including numbers of oocytes retrieved, MII oocytes, 2PN, blastocysts, good-quality blastocysts, and usable blastocysts after biopsy, as well as rates of oocyte yield, blastocyst formation, good-quality blastocysts, and moderate or severe OHSS. Univariable and multivariable logistic regression analyses were used to identify potential confounders that may be independently associated with cumulative live birth.ResultsIn NOR, the cumulative LBR of PPOS protocol was significantly lower than that of GnRH antagonists (28.4% vs. 40.7%; P=0.004). In multivariable analysis, the PPOS protocol was negatively associated with cumulative LBR (adjusted OR=0.556; 95% CI, 0.377-0.822) compared to GnRH antagonists after adjusting for potential confounders. The number and ratio of good-quality blastocysts were significantly reduced in PPOS protocol compared to GnRH antagonists (2.82 ± 2.83 vs. 3.20 ± 2.79; P=0.032 and 63.9% vs. 68.5%; P=0.021), while numbers of oocytes, MII oocytes and 2PN did not show any significant difference between GnRH antagonist and PPOS protocols. PCOS patients had similar outcomes as NOR. The cumulative LBR of PPOS group appeared to be lower than that of GnRH antagonists (37.4% vs. 46.1%; P=0.151), but not significantly. Meanwhile, the proportion of good-quality blastocysts in PPOS protocol was also lower compared to GnRH antagonists (63.5% vs. 68.9%; P=0.014). In patients with POR, the cumulative LBR of PPOS protocol was comparable to that of GnRH antagonists (19.2% vs. 16.7%; P=0.772). There was no statistical difference in the number and rate of good-quality blastocysts between the two protocols in POR, while the proportion of good-quality blastocysts appeared to be higher in PPOS group compared to GnRH antagonists (66.7% vs. 56.3%; P=0.182). In addition, the number of usable blastocysts after biopsy was comparable between the two protocols in three populations.ConclusionThe cumulative LBR of PPOS protocol in PGT cycles is lower than that of GnRH antagonists in NOR. In patients with PCOS, the cumulative LBR of PPOS protocol appears to be lower than that of GnRH antagonists, albeit lacking statistical difference, whereas in patients with diminished ovarian reserve, the two protocols were comparable. Our findings suggest the need for caution when choosing PPOS protocol to achieve live births, especially for normal and high ovarian responders.</p
The characteristics of eligible studies on DCM considered in the meta-analysis.
<p>DCM, dilated cardiomyopathy; NA, not available; EF, ejection fraction; LV, left ventricular.</p
Methanol to Olefins over H‑MCM-22 Zeolite: Theoretical Study on the Catalytic Roles of Various Pores
H-MCM-22
zeolite bears three types of pores, supercages, sinusoidal
channels, and pockets, and exhibits excellent catalytic performance
in the process of methanol to olefins (MTO); however, the catalytic
role that each type plays in MTO is still unclear. In this work, density
functional theory considering dispersive interactions (DFT-D) was
used to elucidate the contributions of various pores in H-MCM-22 to
MTO. The results demonstrated that these three types of pores are
different in their catalytic action on MTO, because of the large differences
in pore size and shape that determine the space confinement and electrostatic
stabilization effects. The formation of propene is predicted to take
place in the supercages, where propene can be effectively produced
through both polyMB and alkene cycles, with a relatively low free
energy barrier as well as low enthalpy barrier and entropy loss for
the rate-determining steps. In the sinusoidal channels, the free energy
barrier of the methylation and cracking steps is elevated due to the
space confinement and the reactivity of alkenes is also markedly depressed
in the narrow channels, in comparison with those in the supercages;
as a result, the contribution of the sinusoidal channels to the entire
propene formation is minor. Meanwhile, the pockets are probably detrimental
to MTO, as certain large intermediates such as 1,1,2,6-tetramethyl-4-isopropylbenzenium
cations are easily formed in the pockets but are difficult to decompose
due to the lack of an electrostatic stabilization effect from the
zeolite framework, which elevates the total free energy barrier and
may lead to a rapid deactivation of these active sites. In comparison
with the difference in pore size and structure, the difference of
various pores in the acid strength of the active sites exhibits an
insignificant effect on their catalytic behaviors in MTO. The theoretical
insights in this work are conducive to a subsequent investigation
on the MTO mechanism and the development of better MTO catalysts and
reaction processes
The distribution of polymorphism for cases and controls.
<p>DCM, dilated cardiomyopathy; HCM, hypertrophic cardiomyopathy; NA, not available.</p
The characteristics of eligible studies on HCM considered in the meta-analysis.
<p>HCM, hypertrophic cardiomyopathy; NA, not available; LV, left ventricular.</p
Discovery of Novel Acetohydroxyacid Synthase Inhibitors as Active Agents against <i>Mycobacterium tuberculosis</i> by Virtual Screening and Bioassay
Acetohydroxyacid synthase (AHAS) has been regarded as
a promising
drug target against <i>Mycobacterium tuberculosis</i> (MTB)
as it catalyzes the biosynthesis of branched-chain amino acids. In
this study, 23 novel AHAS inhibitors were identified through molecular
docking followed by similarity search. The determined IC<sub>50</sub> values range from 0.385 ± 0.026 μM to >200 μM
against
bacterium AHAS. Five of the identified compounds show significant
in vitro activity against H37Rv strains (MICs in the range of 2.5–80
mg/L) and clinical MTB strains, including MDR and XDR isolates. More
impressively, compounds <b>5</b> and <b>7</b> can enhance
the killing ability against macrophages infected pathogen remarkably.
This study suggests our discovered inhibitors can be further developed
as novel anti-MTB therapeutics targeting AHAS
Evolution of Aromatic Species in Supercages and Its Effect on the Conversion of Methanol to Olefins over H‑MCM-22 Zeolite: A Density Functional Theory Study
H-MCM-22
zeolite is a potential catalyst for the conversion of
methanol to olefins (MTO). Previous studies indicated that three types
of pores in H-MCM-22, viz., the supercages, sinusoidal channels, and
pockets, are different in their catalytic action; however, the evolution
of aromatic species in the supercages and its effect on MTO are still
highly controversial. In this work, density functional theory considering
dispersive interactions (DFT-D) was used to investigate the evolution
of aromatic species including their formation, reactivity, and deactivation
behavior in the supercages; the active role of the supercages in catalyzing
MTO was elucidated. The results demonstrated that benzene can be generated
in the supercages through aromatization of light olefins; after that,
polymethylbenzenes (polyMBs) are formed through methylations, in competition
with the construction of naphthalenic species. Both polyMBs (e.g.,
hexamethylbenzene) and polymethylnaphthalenes (polyMNs, e.g. dimethylnaphthalene)
exhibit high reactivity as the hydrocarbon pool species in forming
light olefins. Owing to the appropriate electrostatic stabilization
and space confinement effects, naphthalenic species in the supercages
are inclined to serve as the active intermediates to produce light
olefins rather than act as the coke precursors in the initial period
of MTO; as a result, the supercages contribute actively to the initial
activity of H-MCM-22 in MTO, though they may be prone to deactivation
in the later reaction stage in comparison with the sinusoidal channels.
The insights shown in this work help to clarify the evolution of aromatic
species and the active role of the supercages in MTO over H-MCM-22,
which is of benefit to the development of better MTO catalysts and
reaction processes