A rare case of an infected aortoiliac graft complicated with Eggerthella lenta bacteremia and septic shock.

We describe the successful medical management of an infected aorto-bi-Iliac endograft. In this case report, we provide an example of a patient with an infected aorto-bi-iliac endograft and how appropriate medical management may result in a positive outcome. We report a case of a 67-year-old man with several medical comorbidities who developed aorto-bi-iliac endograft infection one year after graft placement. The patient presented to our E.R. with fever, lethargy, tachycardia, tachypnea, and hypotension. The diagnosis of an infected endograft was established after excluding any other possible source of infection plus the strong radiological evidence by computed tomographic scan and WBCs labeled Indium-111 tropolone scan. Blood cultures revealed the development of Eggerthella lenta, Escherichia coli Extended-spectrum beta-lactamase (ESBL), and Enterococcus Faecalis. To our knowledge, this is a rare case of an infected endograft and bacteremia due to Eggerthella lenta. After the administration of vancomycin and Meropenem, no improvements were noted to the patient's clinical condition. However, upon the administration of Tigecycline, the patient's clinical condition improved. Two days later, repeat blood cultures were negative. After completion of the course of antibiotics and stabilization of other comorbidities, the patient was discharged home with long term antibiotic therapy under close control of inflammation markers.

Atypical Myocardial Infarction with Apical Thrombus and Systemic Embolism: A Rare Presentation of Likely JAK2 V617F-Positive Myeloproliferative Neoplasm.

A few types of myeloproliferative neoplasms may be significant for Janus-associated kinase 2 mutation, JAK2 V617F, including polycythemia vera, essential thrombocythemia, and primary myelofibrosis. The prevalence of JAK2 mutation is low in the general population but higher in patients with myeloproliferative neoplasms. Some patients with JAK2 V617F-positive essential thrombocythemia are asymptomatic, but others may develop hemorrhagic or thromboembolic complications. Thromboembolism may occur in vessels of high flow organs like the heart and, thereby, present as myocardial infarction. Nonetheless, these patients are usually symptomatic with complaints of chest pain, for example. Atypical (asymptomatic) myocardial infarction with mild thrombocytosis may be the first clue for possible essential thrombocythemia with JAK2 V617F. In this report, we discuss a case of atypical (asymptomatic) myocardial infarction with secondary thromboembolism in a patient positive for JAK2 V617F with a likely myeloproliferative neoplasm.

COVID-19: The Case of Three Patients with the Same Diagnosis but Different Clinical and Laboratory Features.

SARS-CoV-2 is an RNA virus that causes COVID-19, which has been responsible for the pandemic that was declared in early 2020. Its pathological effect is majorly in the respiratory tract, but its full pathogenicity remains a mystery. Symptoms associated with COVID-19 include fever, cough, and shortness of breath. Some patients develop other symptoms like diarrhea. However, it is possible for other organs to be affected including the central nervous system, liver, and blood cells. The purpose of this case series is to unravel other factors associated with this disease, so we report three cases of COVID-19 that were hospitalized during the pandemic.

Severe Malaria: A Case of a Significant Rapid Rise in the Parasite Level.

Malaria is transmitted by the Plasmodium parasite, and most of the cases reported in the United States are often as a result of patients with recent return from endemic areas. Prompt diagnosis and treatment, particularly if there is severe parasitemia and drug failure, is essential in preventing mortality. Our patient had an unusual rapid rise in parasite but susceptible to intravenous artesunate.

Remote Raman measurements of minerals, organics, and inorganics at 430 m range.

Raman spectroscopy is a characterization technique that is able to analyze and detect water or water-bearing minerals, minerals, and organic materials that are of special interest for planetary science. Using a portable pulsed remote Raman system with a commercial 8 in. (203.2 mm) telescope, a frequency doubled Nd-YAG-pulsed laser, and a spectrometer equipped with an intensified CCD camera, we acquired good quality Raman spectra of various materials from a 430 m standoff distance during daylight with detection times of 1-10 s, in a realistic context in which both the exciting source and the detector are part of the same measurement system. Remote Raman spectra at this distance provided unambiguous detection of compounds such as water and water ice, dry ice, sulfur, sulfates, various minerals and organics, and atmospheric gases. This research work demonstrates significant improvement in the remote Raman technique as well as its suitability for solar system exploration.

A combined crossed molecular beam and theoretical investigation of the reaction of the meta-tolyl radical with vinylacetylene--toward the formation of methylnaphthalenes.

Crossed molecular beam experiments and electronic structure calculations on the reaction of the meta-tolyl radical with vinylacetylene were conducted to probe the formation of methyl-substituted naphthalene isomers. We present the compelling evidence that under single collision conditions 1- and 2-methylnaphthalene can be formed without an entrance barrier via indirect scattering dynamics through a bimolecular collision of two non-PAH reactants: the meta-tolyl radical and vinylacetylene. The electronic structure calculations, conducted at the UCCSD(T)-F12b/cc-pVDZ//UM06-2x/cc-pVTZ + ZPE(UM06-2x/cc-pVTZ) level of theory, reveal that this reaction is initiated by the barrierless addition of the meta-tolyl radical to the terminal vinyl carbon (C1) of vinylacetylene, via a van-der-Waals complex implying that this mechanism can play a key role in forming methyl-substituted PAHs in low temperature extreme environments such as the low temperature interstellar medium and hydrocarbon-rich atmospheres of planets and their moons in the outer solar system. The reaction mechanism, proposed from the C11H11 potential energy surface, involves a sequence of isomerizations involving hydrogen transfer and ring closure, followed by hydrogen dissociation, which eventually leads to 1- and 2-methylnaphthalene in an overall exoergic process.

Lyman α photolysis of solid nitromethane (CH3NO2) and D3-nitromethane (CD3NO2)--untangling the reaction mechanisms involved in the decomposition of model energetic materials.

Solid nitromethane (CH3NO2) along with its isotopically labelled counterpart D3-nitromethane (CD3NO2) ices were exposed to Lyman α photons to investigate the mechanism involved in the decomposition of energetic materials in the condensed phase. The chemical processes in the ices were monitored online and in situ via infrared spectroscopy complimented by temperature programmed desorption studies utilizing highly sensitive reflectron time-of-flight mass spectrometry coupled with pulsed photoionization (ReTOF-PI) at 10.49 eV. The infrared data revealed the formation of cis-methylnitrite (CH3ONO), formaldehyde (H2CO), water (H2O), carbon monoxide (CO), and carbon dioxide (CO2). Upon sublimation of the irradiated samples, three classes of higher molecular weight products, which are uniquely formed in the condensed phase, were identified via ReTOF-PI: (i) nitroso compounds [nitrosomethane (CH3NO), nitrosoethane (C2H5NO), nitrosopropane (C3H7NO)], (ii) nitrite compounds [methylnitrite (CH3ONO), ethylnitrite (C2H5ONO), propylnitrite (C3H7ONO)], and (iii) higher molecular weight molecules [CH3NONOCH3, CH3NONO2CH3, CH3OCH2NO2, ONCH2CH2NO2]. The mechanistical information obtained in the present study suggest that the decomposition of nitromethane in the condensed phase is more complex compared to the gas phase under collision-free conditions opening up not only hitherto unobserved decomposition pathways of nitromethane (hydrogen atom loss, oxygen atom loss, retro carbene insertion), but also the blocking of several initial decomposition steps due to the 'matrix cage effect'.

A crossed molecular beam and ab initio study on the formation of 5- and 6-methyl-1,4-dihydronaphthalene (C11H12) via the reaction of meta-tolyl (C7H7) with 1,3-butadiene (C4H6).

The crossed molecular beam reactions of the meta-tolyl radical with 1,3-butadiene and D6-1,3-butadiene were conducted at collision energies of 48.5 kJ mol(-1) and 51.7 kJ mol(-1). The reaction dynamics propose a complex-forming reaction mechanism via addition of the meta-tolyl radical with its radical center either to the C1 or C2 carbon atom of the 1,3-butadiene reactant forming two distinct intermediates, which are connected via migration of the meta-tolyl group. Considering addition to C1 proceeds by formation of a van-der-Waals complex below the energy of the separated reactants, we propose that in cold molecular clouds holding temperatures as low as 10 K, the reaction of the meta-tolyl radical with 1,3-butadiene is de-facto barrier less. At elevated temperatures such as in combustion processes, the reaction can also proceed via addition to C2 by overcoming the entrance barrier to addition (11 kJ mol(-1)). Eventually, the resonantly stabilized free radical intermediate C11H13 undergoes isomerization to a cis form, followed by rearrangement through two distinct ring closures at the para- and ortho-position of tolyl radical to yield cyclic intermediates. These intermediates then emit a hydrogen atom forming 6- and 5-methyl-1,4-dihydronaphthalene via tight exit transition states. The steady state branching ratio, 70.0% and 29.2%, at the collision energy of 51.7 kJ mol(-1), of 6- and 5-methyl-1,4-dihydronaphthalene, respectively, is determined mainly by the rates of reverse ring opening of cyclic intermediates. The formation of the thermodynamically less stable 1-meta-tolyl-trans-1,3-butadiene was found to be a less important pathway (0.8%). The reaction of the meta-tolyl radical with 1,3-butadiene leads without entrance barrier to two methyl substituted PAH derivatives holding 1,4-dihydronapthalene cores: 5- and 6-methyl-1,4-dihydronaphthalene thus providing a barrierless route to odd-numbered PAH derivatives under single collision conditions.

Formation of 2- and 1-methyl-1,4-dihydronaphthalene isomers via the crossed beam reactions of phenyl radicals (C6H5) with isoprene (CH2C(CH3)CHCH2) and 1,3-pentadiene (CH2CHCHCHCH3).

Crossed molecular beam reactions were exploited to elucidate the chemical dynamics of the reactions of phenyl radicals with isoprene and with 1,3-pentadiene at a collision energy of 55 ± 4 kJ mol(-1). Both reactions were found to proceed via indirect scattering dynamics and involve the formation of a van-der-Waals complex in the entrance channel. The latter isomerized via the addition of the phenyl radical to the terminal C1/C4 carbon atoms through submerged barriers forming resonantly stabilized free radicals C11H13, which then underwent cis-trans isomerization followed by ring closure. The resulting bicyclic intermediates fragmented via unimolecular decomposition though the atomic hydrogen loss via tight exit transition states located 30 kJ mol(-1) above the separated reactants in overall exoergic reactions forming 2- and 1-methyl-1,4-dihydronaphthalene isomers. The hydrogen atoms are emitted almost perpendicularly to the plane of the decomposing complex and almost parallel to the total angular momentum vector ('sideways scattering') which is in strong analogy to the phenyl-1,3-butadiene system studied earlier. RRKM calculations confirm that 2- and 1-methyl-1,4-dihydronaphthalene are the dominating reaction products formed at levels of 97% and 80% in the reactions of the phenyl radical with isoprene and 1,3-pentadiene, respectively. This barrier-less formation of methyl-substituted, hydrogenated PAH molecules further supports our understanding of the formation of aromatic molecules in extreme environments holding temperatures as low as 10 K.

Reactive pathways in the chlorobenzene-ammonia dimer cation radical: new insights from experiment and theory.

Building upon our recent studies of noncovalent interactions in chlorobenzene and bromobenzene clusters, in this work we focus on interactions of chlorobenzene (PhCl) with a prototypical N atom donor, ammonia (NH3). Thus, we have obtained electronic spectra of PhCl···(NH3)n (n = 1-3) complexes in the region of the PhCl monomer S0 -S1 (ππ*) transition using resonant 2-photon ionization (R2PI) methods combined with time-of-flight mass analysis. Consistent with previous studies, we find that upon ionization the PhCl···NH3 dimer cation radical reacts primarily via Cl atom loss. A second channel, HCl loss, is identified for the first time in R2PI studies of the 1:1 complex, and a third channel, H atom loss, is identified for the first time. While prior studies have assumed the dominance of a π-type complex, we find that the reactive complex corresponds instead to an in-plane σ-type complex. This is supported by electronic structure calculations using density functional theory and post-Hartree-Fock methods and Franck-Condon analysis. The reactive pathways in this system were extensively characterized computationally, and consistent with results from previous calculations, we find two nearly isoenergetic arenium ions (Wheland intermediates; denoted WH1, WH2), which lie energetically below the initially formed dimer cation radical complex. At the energy of our experiment, intermediate WH1, produced from ipso-addition, is not stable with respect to Cl or HCl loss, and the relative branching between these channels observed in our experiment is well reproduced by microcanonical transition state theory calculations based upon the calculated parameters. Intermediate WH2, where NH3 adds ortho to the halogen, decomposes over a large barrier via H atom loss to form protonated o-chloroaniline. This channel is not open at the (2-photon) energy of our experiments, and it is suggested that photodissociation of a long-lived (i.e., several ns) WH2 intermediate leads to the observed products.

π-Stacking, C-H/π, and halogen bonding interactions in bromobenzene and mixed bromobenzene-benzene clusters.

Noncovalent interactions play an important role in many chemical and biochemical processes. Building upon our recent study of the homoclusters of chlorobenzene, where π-π stacking and CH/π interactions were identified as the most important binding motifs, in this work we present a study of bromobenzene (PhBr) and mixed bromobenzene-benzene clusters. Electronic spectra in the region of the PhBr monomer S0-S1 (ππ*) transition were obtained using resonant two-photon ionization (R2PI) methods combined with time-of-flight mass analysis. As previously found for related systems, the PhBr cluster spectra show a broad feature whose center is red-shifted from the monomer absorption, and electronic structure calculations indicate the presence of multiple isomers and Franck-Condon activity in low-frequency intermolecular modes. Calculations at the M06-2X/aug-cc-pVDZ level find in total eight minimum energy structures for the PhBr dimer: four π-stacked structures differing in the relative orientation of the Br atoms (denoted D1-D4), one T-shaped structure (D5), and three halogen bonded structures (D6-D8). The calculated binding energies of these complexes, corrected for basis set superposition error (BSSE) and zero-point energy (ZPE), are in the range of -6 to -24 kJ/mol. Time-dependent density functional theory (TDDFT) calculations predict that these isomers absorb over a range that is roughly consistent with the breadth of the experimental spectrum. To examine the influence of dipole-dipole interaction, R2PI spectra were also obtained for the mixed PhBr···benzene dimer, where the spectral congestion is reduced and clear vibrational structure is observed. This structure is well-simulated by Franck-Condon calculations that incorporate the lowest frequency intermolecular modes. Calculations find four minimum energy structures for the mixed dimer and predict that the binding energy of the global minimum is reduced by ~30% relative to the global minimum PhBr dimer structure.

On π-stacking, C-H/π, and halogen bonding interactions in halobenzene clusters: resonant two-photon ionization studies of chlorobenzene.

Noncovalent interactions such as hydrogen bonding, π-π stacking, CH/π interactions, and halogen bonding play crucial roles in a broad spectrum of chemical and biochemical processes, and can exist in cooperation or competition. Here we report studies of the homoclusters of chlorobenzene, a prototypical system where π-π stacking, CH/π interactions, and halogen bonding interactions may all be present. The electronic spectra of chlorobenzene monomer and clusters (Clbz)(n) with n = 1-4 were obtained using resonant 2-photon ionization in the origin region of the S(0)-S(1) (ππ*) state of the monomer. The cluster spectra show in all cases a broad spectrum whose center is redshifted from the monomer absorption. Electronic structure calculations aid in showing that the spectral broadening arises in large part from inhomogeneous sources, including the presence of multiple isomers and Franck-Condon (FC) activity associated with geometrical changes induced by electronic excitation. Calculations at the M06-2x/aug-cc-pVDZ level find in total five minimum energy structures for the dimer, four π-stacked structures, and one T-shaped, and six representative minimum energy structures were found for the trimer. The calculated time-dependent density functional theory spectra using range-separated and meta-GGA hybrid functionals show that these isomers absorb over a range that is roughly consistent with the breadth of the experimental spectra, and the calculated absorptions are redshifted with respect to the monomer transition, in agreement with experiment. Due to the significant geometry change in the electronic transition, where for the dimer a transition from a parallel displaced to sandwich structure occurs with a reduced separation of the two monomers, significant FC activity is predicted in low frequency intermolecular modes.