ABSTRACT
Full arch implant-supported restorations are a common treatment modality for patients with a terminal dentition or an edentulous mouth. Several mechanical and biological factors that contribute to complications or failure are already extensively documented. Some patients receiving complex implant-based treatment plans also suffer from obstructive sleep apnea (OSA). The use of a continuous positive airway pressure (CPAP) mask in some of these patients is a lesser-known factor that could contribute to implant complications or failures. This article describes how the use of a CPAP machine may be a risk factor in implant dentistry and describes a patient whose use of a CPAP machine and mask led to a catastrophic failure of mandibular full arch dental implants.
Subject(s)
Dental Implants , Immediate Dental Implant Loading , Jaw, Edentulous , Mouth, Edentulous , Humans , Dental Implants/adverse effects , Continuous Positive Airway Pressure/adverse effects , Dental Implantation, Endosseous , Mouth, Edentulous/surgery , Dental Prosthesis, Implant-Supported/adverse effects , Dental Restoration Failure , Treatment Outcome , Follow-Up Studies , Jaw, Edentulous/surgeryABSTRACT
This paper compares variations on a structure model derived from an X-ray diffraction data set from a solid solution of chalcogenide derivatives of cis-1,2-bis-(di-phenyl-phosphan-yl)ethyl-ene, namely, 1,2-(ethene-1,2-di-yl)bis-(di-phenyl-phoshpine sulfide/selenide), C26H22P2S1.13Se0.87. A sequence of processes are presented to ascertain the composition of the crystal, along with strategies for which aspects of the model to inspect to ensure a chemically and crystallographically realistic structure. Criteria include mis-matches between F obs 2 and F calc 2, plots of |F obs| vs |F calc|, residual electron density, checkCIF alerts, pitfalls of the OMIT command used to suppress ill-fitting data, comparative size of displacement ellipsoids, and critical inspection of inter-atomic distances. Since the structure is quite small, solves easily, and presents a number of readily expressible refinement concepts, we feel that it would make a straightforward and concise instructional piece for students learning how to determine if their model provides the best fit for the data and show students how to critically assess their structures.
ABSTRACT
The crystal structures of (Z)-(ethene-1,2-di-yl)bis-(di-phenyl-phosphine sulfide), C26H22P2S2 (I), along with its complex with PtII dichloride, di-chlorido[(Z)-(ethene-1,2-di-yl)bis-(di-phenyl-phosphine sulfide)-κ2 S,S']platinum(II), [PtCl2(C26H22P2S2)] (II), are described here. Compound I features P=S bond lengths of 1.9571â (15) and 1.9529â (15)â Å, with a torsion angle of 166.24â (7)° between the two phosphine sulfide groups. The crystal of compound I features both intra-molecular C-Hâ¯S hydrogen bonds and π-π inter-actions. Mol-ecules of compound I are held together with inter-molecular π-π and C-Hâ¯π inter-actions to form chains that run parallel to the z-axis. The inter-molecular C-Hâ¯π inter-action has a Hâ¯Cg distance of 2.63â Å, a Dâ¯Cg distance of 3.573â (5)â Å and a D-Hâ¯Cg angle of 171° (where Cg refers to the centroid of one of the phenyl rings). These chains are linked by relatively long C-Hâ¯S hydrogen bonds with Dâ¯A distances of 3.367â (4) and 3.394â (4)â Å with D-Hâ¯A angles of 113 and 115°. Compound II features Pt-Cl and Pt-S bond lengths of 2.3226â (19) and 2.2712â (19)â Å, with a P=S bond length of 2.012â (3)â Å. The PtII center adopts a square-planar geometry, with Cl-Pt-Cl and S-Pt-S bond angles of 90.34â (10) and 97.19â (10)°, respectively. Mol-ecules of compound II are linked in the crystal by inter-molecular C-Hâ¯Cl and C-Hâ¯S hydrogen bonds.
ABSTRACT
Long-acting (LA) human immunodeficiency virus-1 (HIV-1) antiretroviral therapy characterized by a ≥1 month dosing interval offers significant advantages over daily oral therapy. However, the criteria for compounds that enter clinical development are high. Exceptional potency and low plasma clearance are required to meet dose size requirements; excellent chemical stability and/or crystalline form stability is required to meet formulation requirements, and new antivirals in HIV-1 therapy need to be largely free of side effects and drug-drug interactions. In view of these challenges, the discovery that capsid inhibitors comprising a quinazolinone core tolerate a wide range of structural modifications while maintaining picomolar potency against HIV-1 infection in vitro, are assembled efficiently in a multi-component reaction, and can be isolated in a stereochemically pure form is reported herein. The detailed characterization of a prototypical compound, GSK878, is presented, including an X-ray co-crystal structure and subcutaneous and intramuscular pharmacokinetic data in rats and dogs.
Subject(s)
Anti-HIV Agents , HIV Infections , HIV-1 , Humans , Rats , Animals , Dogs , Capsid , Capsid Proteins , Quinazolinones/pharmacology , Quinazolinones/therapeutic use , Anti-HIV Agents/pharmacokinetics , HIV Infections/drug therapyABSTRACT
The crystal structure of the title compound, [AuCl(C16H13PS)], is reported. The mol-ecular structure features a nearly linear arrangement of the chloride and phosphino ligands around the gold(I) center, with a P-Au-Cl bond angle of 179.42â (9)°. The Au-P and Au-Cl bond lengths are 2.226â (2) and 2.287â (2)â Å, respectively. The geometry of the groups bonded to the phospho-rus atom of the ligand is a slightly distorted tetra-hedron. The phenyl and thienyl rings of the ligand are extensively disordered, with the thienyl refined over all three possible positions on the phospho-rus atom. The relative occupancy ratio between these positions was found to be 0.406â (3):0.406â (2):0.188â (2). One of the major thienyl ring positions with the relative occupancy of 0.406 was modeled as two rotational isomers around the C-P bond with a relative occupancy ratio of 0.278â (3):0.128â (3). Inter-molecular C-Hâ¯π inter-actions present in the crystal lattice link mol-ecules of the title compound together to form a complex three-dimensional network.
ABSTRACT
A novel synthesis of diphenyl(2-thienyl)phosphine, along with its' oxide, sulfide and selenide derivatives, is reported here. These phosphines have been characterized by NMR, IR, MS and X-Ray crystallography. The phosphine oxide derivative was reacted with a selection of lanthanide(III) nitrates and triflates, LnX3, to give the resultant metal-ligand complexes. These complexes have also been characterized by NMR, IR, MS and X-Ray crystallography. Single crystal X-Ray diffraction data shows a difference in metal-ligand complex stoichiometry and stereochemistry depending on the counteranion (nitrate vs. triflate). The [Ln(Ar3PîO)3(NO3)3] ligand-nitrate complexes are nine-coordinate to the metal in the solid state (bidentate nitrate), featuring a 1 : 3 lanthanide-ligand ratio and bear an overall octahedral arrangement of the six, coordinated ligands. Our [Ln(Ar3PîO)3(NO3)3] ligand-nitrate complexes gave three examples of fac-stereochemistry, where mer-stereochemistry is almost universally observed in the literature of highly related [Ln(Ar3PîO)3(NO3)3] complexes. For the Tb complexes, two different arrangements of the ligands around the metal were observed in the solid state for [Tb(Ar3PîO)3(NO3)3] and [Tb(Ar3PîO)4(OTf)2] [OTf]. [Tb(Ar3PîO)3(NO3)3] is strictly nine-coordinate, ligand mer-stereochemistry in the solid state, and [Tb(Ar3PîO)4(OTf)2] [OTf] is strictly octahedral, six-coordinate, with a square-planar stereochemical arrangement of the phosphine oxide ligands around the metal.
Subject(s)
Coordination Complexes , Lanthanoid Series Elements , Phosphines , Biphenyl Compounds , Coordination Complexes/chemistry , Lanthanoid Series Elements/chemistry , Ligands , Nitrates/chemistry , Nitrogen Oxides , Oxides , Phosphines/chemistryABSTRACT
BACKGROUND: Reactive risk assessments (RRAs) such as incident reporting and root cause analysis (RCA), as well as proactive risk assessments (PRAs) such as failure mode and effects analysis, are generally conducted independently in health care. Literature promotes combining risk assessment techniques. This concept builds on previous methodologies and presents an innovative, scalable, and generalizable risk assessment methodology. METHODS: A Combined Proactive Risk Assessment (CPRA) technique entails combining incident reports (RRAs), combining proactive risk assessments (PRAs), and merging components of PRA and RRA. Using specific keywords, this technique aligns patient safety reporting data with process steps and failure modes to assess risk within any of the process steps. This technique was tested by using PRAs from several Veterans Health Administration (VHA) facilities and national patient safety data from the VHA National Center for Patient Safety's database. Reported events and RCAs related to the outpatient blood draw process were used for this illustration. Repeatability was determined by independently applying the technique to two years of data and auditing results. RESULTS: Aggregating PRAs from multiple facilities identified 220% more failure modes; and integrating incident reports into PRA identified 310% more failure modes than the single facility average. Overlaying safety reports onto a comprehensive process flow diagram revealed that 85.8% of events occurred in three of seven process steps. Accuracy of this technique was generally above 85%. CONCLUSION: This technique is promising for identifying vulnerable points in health care processes or to compliment a traditional PRA. Single PRAs are less likely to identify all potential failures or focus on the most hazardous process steps. This technique may aid in assessing key health care processes at an enterprise level.
Subject(s)
Patient Safety , Root Cause Analysis , Delivery of Health Care , Health Facilities , Humans , Risk AssessmentABSTRACT
AbstractIn 1898, Herbert and Alice Walter started a 5-year survey of birds in Lincoln Park-the largest park in Chicago, Illinois-and summarized their data in an urban birding field guide, Wild Birds in City Parks. Twenty-nine years later, William Dreuth compared the relative frequency of species in the Walters' study to that in his own 5-year Lincoln Park survey. Between 2012 and 2015, we replicated these surveys to investigate a century of bird diversity and community composition change in urban Chicago. While species richness did not change, community composition did. We found that (1) species with a greater diet breadth and (2) species that increased in statewide occupancy were more likely to increase in frequency over time. We conclude that factors at multiple scales brought temporal changes to Chicago's bird community. Overall, this survey highlights the slow and subtle ways in which species may respond to a century of urban intensification.
Subject(s)
Biodiversity , Birds , Animals , Animals, Wild , Cities , EcosystemABSTRACT
OBJECTIVES: The Veterans Health Administration maintains national patient safety event reporting and root cause analysis (RCA) databases. These were reviewed to understand the prevalence of and provide insight into patient misidentification. The results were compared with a high-reliability health care framework. METHODS: We reviewed patient safety reports and RCA reports to identify and categorize patient identification-related events from October 1, 2016, to September 30, 2018. We analyzed 3232 patient safety reports and 67 RCAs, aggregated the findings, and compared them against The Joint Commission's High Reliability Health Care Maturity Model. RESULTS: Patient misidentification occurred in both inpatient and outpatient settings, for which the ratio of adverse events to close calls was similar. The ratio of adverse events to close calls varied for specific care areas. The most common RCA event characteristic was Two identifiers not used (39%). The most common failure mode was Procedure performed on wrong patient (31%). Issues related to policy and processes accounted for 42% of the root causes. Actions taken were primarily related to policy, process, and staff training/education (56%); these actions were rated as effective by the reporting facilities. CONCLUSIONS: Patient misidentification is prevalent in both the inpatient and outpatient settings. However, specific care areas reported more close calls, an indicator of good safety culture. There were associations between policy and process issues, consistent use of 2 identifiers, and misidentification events. This review provides insight from the Veterans Health Administration national databases that health care institutions can use to improve their systems.
Subject(s)
Hospitals, Veterans , Veterans Health , Delivery of Health Care , Humans , Medical Errors/prevention & control , Reproducibility of Results , United States , United States Department of Veterans AffairsABSTRACT
We present a new collection of processing techniques, collectively "factorized Kramers-Kronig and error correction" (fKK-EC), for (a) Raman signal extraction, (b) denoising, and (c) phase- and scale-error correction in coherent anti-Stokes Raman scattering (CARS) hyperspectral imaging and spectroscopy. These new methods are orders-of-magnitude faster than conventional methods and are capable of real-time performance, owing to the unique core concept: performing all processing on a small basis vector set and using matrix/vector multiplication afterwards for direct and fast transformation of the entire dataset. Experimentally, we demonstrate that a 703026 spectra image of chicken cartilage can be processed in 70 s (≈ 0.1 ms / spectrum), which is ≈ 70 times faster than with the conventional workflow (≈7.0 ms / spectrum). Additionally, we discuss how this method may be used for machine learning (ML) by re-using the transformed basis vector sets with new data. Using this ML paradigm, the same tissue image was processed (post-training) in ≈ 33 s, which is a speed-up of ≈ 150 times when compared with the conventional workflow.
Subject(s)
Inpatients/statistics & numerical data , Patient Safety/statistics & numerical data , Psychiatric Department, Hospital/statistics & numerical data , Root Cause Analysis , Suicide, Attempted/prevention & control , Suicide, Attempted/statistics & numerical data , Suicide, Completed/prevention & control , Suicide, Completed/statistics & numerical data , Adult , Humans , Retrospective Studies , United States , United States Department of Veterans Affairs/statistics & numerical dataABSTRACT
Potential energy landscape (PEL) concepts have been useful in conceptualizing the effects of intermolecular interactions on dynamic and thermodynamic properties of liquids and glasses. "Basins", or regions of reduced potential energy associated with locally preferred molecular packing are important PEL features. The molecular configurations at the bottom of these basins are referred to as inherent structures (ISs). Experimental methods for directly characterizing PEL features such as these are rare, largely relegating PEL concepts to theory and simulation studies, and impeding their exploration in real systems. Recently, we showed that quasielastic neutron scattering (QENS) data from propylene carbonate (PC) exhibit signatures of picosecond timescale motion that are consistent with intrabasin motion and interbasin transitions [Cicerone et al., J. Chem. Phys., 2017, 146, 054502]. Here we present optically-heterodyne-detected optical Kerr effect (OHD-OKE) spectroscopy studies on PC. The data exhibit signatures of motion within and transitions between basins that agree quantitatively with and extend the QENS results. We show that the librational component of the OKE response corresponds to intrabasin dynamics, and the enigmatic intermediate OKE response corresponds to interbasin transition events. The OKE data extend the measurement range of these parameters and reveal their utility in characterizing PEL features of real systems.
ABSTRACT
The development of economical, low-maintenance, environmentally friendly and effective water filtration techniques can have far-reaching public health, social and economic benefits. In this research, a cost-effective La-modified granular ceramic material made of red art clay and recycled paper fiber was developed for the removal of two major anionic contaminants, As(V) (arsenate) and Cr(VI) (chromate). La modification temperature significantly impacted the resulting composition and properties of the adsorbents, and thus played a crucial role in the adsorbent performance. The La-modified ceramic materials were extensively characterized through scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area measurement, thermal gravimetric analysis (TGA), zeta potential measurements, and Fourier-transform infrared spectroscopy (FTIR) analysis. The characterization results suggested that surface coating by LaONO3-related compounds was critical for As(V) and Cr(VI) adsorption. At the modification temperature of 385 °C, the adsorption of As(V) and Cr(VI) reached maximum, which were 23 mg/g and 13 mg/g, respectively, under circumneutral conditions that are relevant to various aquatic systems. The adsorption kinetics and isotherm, the influence of pH, ionic strength and coexisting anions on As(V) and Cr(VI) adsorption were investigated to further understand both As(V) and Cr(VI) adsorption behavior. Findings from this research showed that La-modified ceramic material made of recycled paper waste represents a cost-effective adsorbent for anionic contaminant removal under environmentally relevant conditions.
ABSTRACT
The title compound, [PtCl2(C26H22P2)]·2CHCl3 (I), is the third monoclinic polymorph of this platinum(II) complex involving the bidentate ligand cis-1,2-bis-(di-phenyl-phosphan-yl)ethyl-ene (cis-dppe) [for the others, see: Oberhauser et al. (1998a â¸). Inorg. Chim. Acta, 274, 143-154, and Oberhauser et al. (1995 â¸). Inorg. Chim. Acta, 238, 35-43]. The structure of compound (I) was solved in the space group P21/c, with one complex mol-ecule in the asymmetric unit along with two solvate chloro-form mol-ecules. The PtII atom is ligated by two P and two Cl atoms in the equatorial plane and has a perfect square-planar coordination sphere. In the crystal, the complex mol-ecule is linked to the chloro-form solvate mol-ecules by C-Hâ¯Cl hydrogen bonds and face-on C-Clâ¯π inter-actions. There are also weak offset π-π inter-actions present [inter-centroid distances are 3.770â (6) and 4.096â (6)â Å], linking the mol-ecules to form supra-molecular sheets that lie in the bc plane.
ABSTRACT
Ultrafast optical Kerr effect (OKE) spectroscopy is a widely used method for studying the depolarized, Raman-active intermolecular dynamics of liquids. Through appropriate manipulation of OKE data, it is possible to determine the reduced spectral density (RSD), which is the Bose-Einstein-corrected, low-frequency Raman spectrum with the contribution of diffusive reorientation removed. OKE RSDs for van der Waals liquids can often be fit well to an empirical function that is the sum of a Bucaro-Litovitz function and an antisymmetrized Gaussian (AG). Although these functions are not directly representative of specific intermolecular dynamics, the AG fit parameters can provide useful insights into the microscopic properties of liquids. Here we show that fits using the AG function are typically not well-determined, and that equally good results can be obtained with a wide range of fitting parameters. We propose the use of a physically motivated constraint on the amplitude of the AG function, and demonstrate that this constraint leads to more intuitive trends in the fit parameters for temperature-dependent RSDs in 1,3,5-trifluorobenzene and hexafluorobenzene.
ABSTRACT
An efficient large-scale synthesis of acid 1, a penultimate precursor to the HCV NS5A inhibitor BMS-986097, along with the final API step are described. Three routes were devised for the synthesis of 1 at the various stages of the program. The third generation route, the one that proved scalable and is the main subject of this paper, features a one-step Michael addition of t-butyl 2-((diphenylmethylene)amino)acetate (24) to (E)-benzyl 4-(1-hydroxycyclopropyl)but-2-enoate (28) followed by cyclization and chiral separation to form 27c, the core skeleton of cap piece 1. The epimerization and chiral resolution of 27c followed by further synthetic manipulations involving the carbamate formation, lactone reduction and cyclization, afforded cyclopropyl pyran 1. A detailed study of diphenylmethane deprotection via acid hydrolysis as well as a key lactone to tetrahydropyran conversion, in order to avoid a side reaction that afforded an alternative cyclization product, are discussed. This synthesis was applied to the preparation of more than 100 g of the final API BMS-986097 for toxicology studies.
Subject(s)
Antiviral Agents/chemical synthesis , Glycine/analogs & derivatives , Imidazoles/chemical synthesis , Pyrans/pharmacology , Pyrrolidines/chemical synthesis , Spiro Compounds/chemical synthesis , Viral Nonstructural Proteins/antagonists & inhibitors , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Imidazoles/chemistry , Imidazoles/pharmacology , Molecular Structure , Pyrans/chemical synthesis , Pyrans/chemistry , Pyrrolidines/chemistry , Pyrrolidines/pharmacology , Spiro Compounds/chemistry , Spiro Compounds/pharmacology , Viral Nonstructural Proteins/metabolismABSTRACT
Solvents for cleaning optics often come into contact with plastic and/or rubber during storage and transfer. To explore the effects that exposure to these materials can have on solvents, we used vibrational sum-frequency-generation spectroscopy to study a silica optic following cleaning with solvents that had come into contact with either low-density polyethylene, high-density polyethylene, or rubber. Our studies show that even brief contact of acetone, methanol, or isopropanol with plastic or rubber can cause otherwise pure solvents to leave a persistent residue.
ABSTRACT
The hepatitis C virus (HCV) NS5B replicase is a prime target for the development of direct-acting antiviral drugs for the treatment of chronic HCV infection. Inspired by the overlay of bound structures of three structurally distinct NS5B palm site allosteric inhibitors, the high-throughput screening hit anthranilic acid 4, the known benzofuran analogue 5, and the benzothiadiazine derivative 6, an optimization process utilizing the simple benzofuran template 7 as a starting point for a fragment growing approach was pursued. A delicate balance of molecular properties achieved via disciplined lipophilicity changes was essential to achieve both high affinity binding and a stringent targeted absorption, distribution, metabolism, and excretion profile. These efforts led to the discovery of BMS-929075 (37), which maintained ligand efficiency relative to early leads, demonstrated efficacy in a triple combination regimen in HCV replicon cells, and exhibited consistently high oral bioavailability and pharmacokinetic parameters across preclinical animal species. The human PK properties from the Phase I clinical studies of 37 were better than anticipated and suggest promising potential for QD administration.
Subject(s)
Antiviral Agents/pharmacology , Antiviral Agents/pharmacokinetics , Benzofurans/pharmacology , Benzofurans/pharmacokinetics , Hepacivirus/drug effects , Hepatitis C/drug therapy , Viral Nonstructural Proteins/antagonists & inhibitors , Allosteric Regulation/drug effects , Allosteric Site/drug effects , Animals , Antiviral Agents/chemistry , Benzofurans/chemistry , Dogs , Drug Discovery , Haplorhini , Hepatitis C/virology , Humans , Male , Molecular Docking Simulation , Rats , Rats, Sprague-Dawley , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/metabolismABSTRACT
The high-frequency portion of the optical Kerr effect (OKE) spectrum of benzene shifts to higher frequency with decreasing temperature at constant pressure. This behavior has been interpreted previously in terms of an increase in librational frequencies due to the decrease in free volume with liquid densification. However, decreasing temperature also provides less access to the more repulsive portion of the intermolecular potential, which would cause the blue edge of the spectrum to red-shift. To explore the relative importance of these phenomena, molecular dynamics simulations of benzene are used to isolate the effects of temperature and density on the spectrum. The simulations show that, at constant density, the high-frequency portion of the spectrum shifts to lower frequency with decreasing temperature. In contrast, at constant temperature, the high-frequency portion of the spectrum shifts to higher frequency with increasing density. These results indicate that density plays a greater role in determining the position of the blue edge of the low-frequency Raman spectrum of benzene than does temperature. Empirical fits show that the effects of changing density or temperature are similar in experimental and simulated OKE spectra. Furthermore, line-shape analysis of simulated spectra under isochoric and isothermal conditions shows that the effects of density and temperature are separable, suggesting that OKE spectroscopy is a viable technique for in situ measurement of the density of van der Waals liquids.