QM/MM Modeling of Vibrational Polariton Induced Energy Transfer and Chemical Dynamics

Vibrational strong coupling (VSC) provides a novel means to modify chemical reactions and energy transfer pathways. To efficiently model chemical dynamics under VSC in the collective regime, herein a hybrid quantum mechanical/molecular mechanical (QM/MM) cavity molecular dynamics (CavMD) scheme is developed and applied to an experimentally studied chemical system. This approach can achieve linear scaling with respect to the number of molecules for a dilute solution under VSC by assuming that each QM solute molecule is surrounded by an independent MM solvent bath. Application of this approach to a dilute solution of Fe(CO)$_5$ in n-dodecane under VSC demonstrates polariton dephasing to the dark modes and polariton-enhanced molecular nonlinear absorption. These simulations predict that strongly exciting the lower polariton may provide an energy transfer pathway that selectively excites the equatorial CO vibrations rather than the axial CO vibrations. Moreover, these simulations also directly probe the cavity effect on the dynamics of the Fe(CO)$_5$ Berry pseudorotation reaction for comparison to recent two-dimensional infrared spectroscopy experiments. This theoretical approach is applicable to a wide range of other polaritonic systems and provides a tool for exploring the use of VSC for selective infrared photochemistry.Comment: 19 pages, 5 figures in the main tex

Correlations between total cell concentration, total adenosine tri-phosphate concentration and heterotrophic plate counts during microbial monitoring of drinking water

The general microbial quality of drinking water is normally monitored by heterotrophic plate counts (HPC). This method has been used for more than 100 years and is recommended in drinking water guidelines. However, the HPC method is handicapped because it is time-consuming and restricted to culturable bacteria. Recently, rapid and accurate detection methods have emerged, such as adenosine tri-phosphate (ATP) measurements to assess microbial activity in drinking water, and flow cytometry (FCM) to determine the total cell concentration (TCC). It is necessary and important for drinking water quality control to understand the relationships among the conventional and new methods. In the current study, all three methods were applied to 200 drinking water samples obtained from two local buildings connected to the same distribution system. Samples were taken both on normal working days and weekends, and the correlations between the different microbiological parameters were determined. TCC in the samples ranged from 0.37–5.61×10<sup>5</sup> cells/ml, and two clusters, the so-called high (HNA) and low (LNA) nucleic acid bacterial groups, were clearly distinguished. The results showed that the rapid determination methods (i.e., FCM and ATP) correlated well (<i>R</i><sup>2</sup>=0.69), but only a weak correlation (<i>R</i><sup>2</sup>=0.31) was observed between the rapid methods and conventional HPC data. With respect to drinking water monitoring, both FCM and ATP measurements were confirmed to be useful and complimentary parameters for rapid assessing of drinking water microbial quality

Use of the physician orders for life-sustaining treatment program in the clinical setting: a systematic review of the literature

The Physician Orders for Life-Sustaining Treatment (POLST) form is a palliative care tool that contains standardized, actionable medical orders. It is designed to ensure that patient treatment preferences are elicited, communicated, and honored throughout the healthcare system. A systematic review of the literature was conducted to evaluate what is currently known about the POLST program and identify directions for future research. Twenty-three research studies focused on POLST use in the clinical setting were identified. A majority of studies have been conducted all or in part in Oregon, with chart review the most frequently used methodology. Research suggests that POLST is most commonly used in older, white patients who are near the end of life. A nonphysician facilitator usually prepares the POLST form for the physician to review and sign. The orders documented on POLST reflect a wide degree of individualization, with only approximately one-third of patients having orders reflecting the lowest level of treatment in all POLST form sections. Clinicians have generally positive attitudes regarding use of POLST yet report a wide range of challenges. POLST alters treatment in a way that is consistent with orders. However, evidence that POLST reflects patient or surrogate treatment preferences is lacking. Research is needed to evaluate the quality of POLST decisions, explore the experiences of patients and their surrogates, develop decision-support tools, improve clinician education, and assess the effect of POLST on care outcomes through intervention and population-based studies

Use of the Physician Orders for Scope of Treatment Program in Indiana Nursing Homes

OBJECTIVES: To assess the use of the Indiana Physician Orders for Scope of Treatment (POST) form to record nursing home (NH) resident treatment preferences and associated practices. DESIGN: Survey. SETTING: Indiana NHs. PARTICIPANTS: Staff responsible for advance care planning in 535 NHs. MEASUREMENTS: Survey about use of the Indiana POST, related policies, and educational activities. METHODS: NHs were contacted by telephone or email. Nonresponders were sent a brief postcard survey. RESULTS: Ninety-one percent (n=486) of Indiana NHs participated, and 79% had experience with POST. Of the 65% of NHs that complete POST with residents, 46% reported that half or more residents had a POST form. POST was most often completed at the time of admission (68%). Only 52% of participants were aware of an existing facility policy regarding use of POST; 80% reported general staff education on POST. In the 172 NHs not using POST, reasons for not using it included unfamiliarity with the tool (23%) and lack of facility policies (21%). CONCLUSION: Almost 3 years after a grassroots campaign to introduce the voluntary Indiana POST program, a majority of NHs were using POST to support resident care. Areas for improvement include creating policies on POST for all NHs, training staff on POST conversations, and considering processes that may enhance the POST conversation, such as finding an optimal time to engage in conversations about treatment preferences other than a potentially rushed admission process

LRP2 mediates folate uptake in the developing neural tube

The low-density lipoprotein (LDL) receptor-related protein 2 (LRP2) is a multifunctional cell surface receptor expressed in the embryonic neuroepithelium. Loss of LRP2 in the developing murine central nervous system (CNS) causes impaired closure of the rostral neural tube at embryonic stage (E) 9.0. Similar neural tube defects (NTDs) have previously been attributed to impaired folate metabolism in mice. We therefore asked whether LRP2 might be required for delivery of folate to neuroepithelial cells during neurulation. Uptake assays in whole embryo cultures showed that LRP2 deficient neuroepithelial cells are unable to mediate uptake of folate bound to soluble folate receptor 1 (sFOLR1). Consequently, folate concentrations are significantly reduced in Lrp2(-/-) embryos compared to control littermates. Moreover, the folic acid dependent gene Alx3 is significantly down regulated in Lrp2 mutants. In conclusion, we show that LRP2 is essential for cellular folate uptake in the developing neural tube, a crucial step for proper neural tube closure

Use of the Physician Orders for Life-Sustaining Treatment Program for Patients Being Discharged from the Hospital to the Nursing Facility

Background: The Physician Orders for Life-Sustaining Treatment (POLST) documents patient preferences as medical orders that transfer across settings with patients., Objectives: The objectives were to pilot test methods and gather preliminary data about POLST including (1) use at time of hospital discharge, (2) transfers across settings, and (3) consistency with prior decisions., Study Design: Descriptive with chart abstraction and interviews., Participants: Participants were hospitalized patients discharged to a nursing facility and/or their surrogates in La Crosse County, Wisconsin., Measurements: POLST forms were abstracted from hospital records for 151 patients. Hospital and nursing facility chart data were abstracted and interviews were conducted with an additional 39 patients/surrogates., Results: Overall, 176 patients had valid POLST forms at the time of discharge from the hospital, and many (38.6%; 68/176) only documented code status. When the whole POLST was completed, orders were more often marked as based on a discussion with the patient and/or surrogate than when the form was used just for code status (95.1% versus 13.8%, p<.001). In the follow-up and interview sample, a majority (90.6%; 29/32) of POLST forms written in the hospital were unchanged up to three weeks after nursing facility admission. Most (71.9%; 23/32) appeared consistent with patient or surrogate recall of prior treatment decisions., Conclusion: POLST forms generated in the hospital do transfer with patients across settings, but are often used only to document code status. POLST orders appeared largely consistent with prior treatment decisions. Further research is needed to assess the quality of POLST decisions

The POLST program: a retrospective review of the demographics of use and outcomes in one community where advance directives are prevalent

OBJECTIVES: Determine the use and utility of the Physician Orders for Life-Sustaining Treatment (POLST) program in a community where powers of attorney for health care (POAHCs) are prevalent. METHODS: A retrospective review of medical record and death certificate data of 400 adults who died between September 1, 2007, and March 31, 2008, in the La Crosse County, Wisconsin community. Demographic and cause-of-death data were collected from death certificates. Information about POAHC, POLST forms, and medical treatments provided in the last 30 days of life were abstracted from decedents' medical records. RESULTS: Sixty-seven percent of decedents had a POLST form, whereas 22% had POAHC alone. In comparison with decedents with POAHC alone, decedents with a POLST form were significantly older (83 versus 77 years, p<0.001), more likely to die in a nursing home than in a hospital (p<0.001), and more likely to die from a terminal or chronic illnesses (97%). Decedents with POLST orders for higher levels of medical treatment received more treatment, and in only two cases was there evidence that treatment was discrepant with POLST orders. In 31% of all POLST forms, the person appointed in the POAHC consented to the POLST orders. CONCLUSIONS: POLST can be a highly effective program to ensure that patient preferences are known and honored in all settings. POAHCs are valuable because they identify appropriate surrogates when patients are incapacitated

First-Principles Approach for Coupled Quantum Dynamics of Electrons and Protons in Heterogeneous Systems

The coupled quantum dynamics of electrons and protons is ubiquitous in many dynamical processes involving light-matter interaction, such as solar energy conversion in chemical systems and photosynthesis. A first-principles description of such nuclear-electronic quantum dynamics requires not only the time-dependent treatment of nonequilibrium electron dynamics but also that of quantum protons. Quantum mechanical correlation between electrons and protons adds further complexity to such coupled dynamics. Here we extend real-time nuclear-electronic orbital time-dependent density functional theory (RT-NEO-TDDFT) to periodic systems and perform first-principles simulations of coupled quantum dynamics of electrons and protons in complex heterogeneous systems. The process studied is electronically excited state intramolecular proton transfer of o-hydroxybenzaldehyde in water and at a silicon (111) semiconductor-molecule interface. These simulations illustrate how environments such as hydrogen-bonding water molecules and an extended material surface impact the dynamical process on the atomistic level. Depending on how the molecule is chemisorbed on the surface, excited state electron transfer from the molecule to the semiconductor surface can inhibit ultrafast proton transfer within the molecule. This work elucidates how heterogeneous environments influence the balance between the quantum mechanical proton transfer and excited electron dynamics. The periodic RT-NEO-TDDFT approach is applicable to a wide range of other photoinduced heterogeneous processes