Aligning patient values and code status: Choice of Diction's Effect (CODE) study.

BACKGROUND: Decisions regarding resuscitation after cardiac arrest are critical from ethical, patient satisfaction, outcome, and healthcare cost standpoints. Physician-reported discussion barriers include topic discomfort, fear of time commitment, and difficulty articulating end-of-life concepts. The influence of language used in these discussions has not been tested. This study explored whether utilizing the alternate term "allow (a) natural death" changed code status decisions in hospitalized patients versus "do not resuscitate" (DNR). METHODS: All patients age 65 and over admitted to a general medicine hospital teaching service were screened (English-speaking, not ICU-level care, no active psychiatric illness, no substance misuse, no active DNR). Participants were randomized to resuscitation discussions with either DNR or "allow natural death" as the "no code" phrasing. Outcomes included patient resuscitation decision, satisfaction with and duration of the conversation, and decision correlation with illness severity and predicted resuscitation success. RESULTS: 102 participants were randomized to the "allow natural death" (N = 49) or DNR (N = 53) arms. The overall "no code" rate for our sample of hospitalized general medicine inpatients age >65 was 16.7%, with 13% in the DNR and 20.4% in the "allow natural death" arms (p = 0.35). Discussion length was similar in the DNR and "allow natural death" arms (3.9 + 3.2 vs. 4.9 + 3.9 minutes), and not significantly different (p = 0.53). Over 90% of participants were highly satisfied with their code status decision, without difference between arms (p = 0.49). CONCLUSIONS: Participants' code status discussions did not differ in "no code" rate between "allow natural death" and DNR arms but were short in length and had high patient satisfaction. Previously reported code status discussion barriers were not encountered. It is appropriate to screen code status in all hospitalized patients regardless of phrasing used.

Factors associated with attitudes toward research MRI in older Asian Americans.

INTRODUCTION: South Asian (SA) and East Asian (EA) older adults represent the fastest-growing racial/ethnic groups of Americans at risk for dementia. While recruiting older SA adults into a brain health study, we encountered unexpected hesitancy toward structural brain magnetic resonance imaging (MRI) analysis and stigmatizing attitudes related to internal locus of control (LoC) for future dementia risks. We hypothesized that support for MRI-related research was influenced by these attitudes as well as personal MRI experience, perceived MRI safety, and concerns for personal risk for future dementia/stroke. METHODS: We developed a brief cross-sectional survey to assess older adults' MRI experiences and perceptions, desire to learn of six incidental findings of increasing impact on health, and attitudes related to dementia (including LoC) and research participation. We recruited a convenience sample of 256 respondents (74% reporting as 50+) from the New Jersey/New York City area to complete the survey (offered in English, Chinese, Korean, and Spanish) and modeled the proportional odds (PO) for favorable attitudes toward research activities. RESULTS: Seventy-seven SA and 84 EA respondents were analyzed alongside 95 White, Black, or Hispanic adults. White (PO = 2.54, p = 0.013) and EA (PO = 2.14, p = 0.019) respondents were both more likely than SA respondents to endorse healthy volunteers' participation in research, and the difference between White and SA respondents was mediated by the latter's greater internal LoC for dementia risks. EA respondents had more worries for future dementia/stroke than SA respondents (p = 0.006) but still shared SA respondents' lower wish (measured by proportion of total) to learn of incidental MRI findings. DISCUSSION: SA-and EA compared to SA-older adults had low desire to learn of incidental MRI findings but had different attitudes toward future dementia/stroke risks. A culturally appropriate protocol to disclose incidental MRI findings may improve SA and EA participation in brain health research. Highlights: Older Asian Americans have limited interest in incidental findings on research MRISouth Asians are most likely to attribute dementia to people's own behaviorsSouth Asians' attitudes mediate lower support for healthy volunteers in researchSouth and East Asians differ in dementia worries and research-related attitudes.

Electronic Health Record Prompt to Improve Lung Cancer Screening in Primary Care.

INTRODUCTION: Lung cancer is the leading cause of cancer death in the U.S. Combusted tobacco use, the primary risk factor, accounts for 90% of all lung cancers. Early detection of lung cancer improves survival, yet lung cancer screening rates are much lower than those of other cancer screening tests. Electronic health record (EHR) systems are an underutilized tool that could improve screening rates. METHODS: This study was conducted in the Rutgers Robert Wood Johnson Medical Group, a university-affiliated network in New Brunswick, NJ. Two novel EHR workflow prompts were implemented on July 1, 2018. These prompts included fields to determine tobacco use and lung cancer screening eligibility and facilitated low-dose computed tomography ordering for eligible patients. The prompts were designed to improve tobacco use data entry, allowing for better lung cancer screening eligibility identification. Data were analyzed in 2022 retrospectively for the period July 1, 2017 to June 30, 2019. The analyses represented 48,704 total patient visits. RESULTS: The adjusted odds of patient record completeness to determine eligibility for low-dose computed tomography (AOR=1.19, 95% CI=1.15, 1.23), eligibility for low-dose computed tomography (AOR=1.59, 95% CI=1.38, 1.82), and whether low-dose computed tomography was ordered (AOR=1.04, 95% CI=1.01, 1.07) all significantly increased after the electronic medical record prompts were implemented. CONCLUSIONS: These findings show the utility and benefit of EHR prompts in primary care settings to increase identification for lung cancer screening eligibility as well as increased low-dose computed tomography ordering.

An Assessment and Comparison of Root Resorption With Two Different Corticotomy Techniques During Anterior Teeth Retraction: A Split Mouth Prospective Clinical Study.

Aim The aim of this prospective split-mouth clinical study is to determine the apical root resorption of anterior teeth in patients with two different methods of corticotomy namely indentation and vertical corticotomy techniques. Methods Sixteen adult patients with bimaxillary protrusion requiring the need for extraction of the first premolars were included in the study. For each patient, the particular method of corticotomy technique was assigned randomly along with the side and the procedure was performed following which retraction forces were applied with the help of a closed coil Niti spring. The root resorption was recorded during the stage of space closure for which two cone beam computed tomography (CBCT) were taken, one before the retraction forces could be applied (T1) and one CBCT (T2) after the space closure had occurred. The apical root resorption was assessed and analyzed both linearly and volumetrically using the CBCT taken at T1 and T2.  Results There was root resorption present after the space closure was complete in both the maxillary and mandibular arches. The amount of root resorption that occurred in the indentation technique was slightly lesser as compared to the vertical corticotomy technique. Conclusion Indentation corticotomy cuts for accelerated tooth movement are considered to be a much safer, more effective method, lesser invasive to the surrounding tissues, technique sensitive, and good regional acceleratory phenomenon (RAP), with a Rapid healing process compared to the vertical corticotomy technique.

Lung Cancer Screening Knowledge and Perceived Barriers Among Physicians in the United States.

Introduction: Lung cancer remains the leading cause of cancer death in the United States and has historically been detected late in its course. Low-dose computed tomography scan (LDCT) reduces lung cancer mortality by 20% and is currently recommended by clinical practice guidelines. However, compared with other cancer screening modalities, LDCT utilization remains low. This study surveyed office-based primary care physicians across the United States to better understand LDCT utilization. Methods: A total of 1500 family and internal medicine physicians selected from the American Medical Association's physician master file were surveyed between April and July 2019 regarding LDCT practices, eligibility, clinical scenarios, and perceived barriers. Results: The American Association for Public Opinion Research response rate 3 was 59% (652 respondents); 599 completed supplemental questions regarding lung cancer screening. A total of 88% of respondents discussed LDCT in the previous year, and 78% had ordered at least one LDCT. Most (59%) knew the tobacco exposure criteria for LDCT and correctly identified appropriate clinical scenarios (49%-86% responded correctly). Less than half of respondents correctly identified the age eligibility criteria (44%-45% responded correctly). In general, male physicians, those who graduated after 1990, and family medicine physicians were more likely to report accurate knowledge regarding LDCT eligibility. The top perceived barriers to LDCT were cost to the patient (48% identified as a major barrier), insurance not covering screening (46% major), and patients being unaware of lung cancer screening (40% major). Conclusion: Knowledge and practices about lung cancer screening are improving, though remain suboptimal. The most common barriers remain cost or insurance-based and suggest the need for a systems-based response to increase awareness and reduce the underutilization of LDCT.

Expression of Poly(Adenosine Diphosphate-Ribose) Polymerase Protein in Breast Cancer.

Background: The use of poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors for breast cancer (BC) therapy is the subject of debate, and there is an urgent need to understand much the expression and prognostic role of the PARP1 protein. In this study, we have compared the expression of PARP between BC and benign breast disease (BBD) patients and also analyzed the association of PARP expression with clinicopathological parameters in BC. Methods: The study consists of 30 patients with newly diagnosed operable BC who were planned for surgery without neoadjuvant chemotherapy and 15 patients of BBD as a control between 2019 and 2021. Immunohistochemical analyses were performed prospectively on tissue samples. Anti-human PARP1 rabbit polyclonal antibody gives strong nuclear positivity. Internal control was the adipose tissue and the BBD acted as the external control. PARP1 expression was evaluated using the multiplicative quickscore method. Results: The mean age for BC patients was 51.30 ± 10.694 years (range: 25-75 years) while BBD was below 30 years. Overexpression of PARP was present in 25 (83.3%) and weak expression in 5 (16.7%) of BC patients compared to BBD, only 2 (13.3%) patients demonstrated an overexpression of PARP, and 13 (86.6%) patients showed weak expression which showed significant association (P < 0.001). In BC, nuclear PARP (nPARP) overexpression was seen in 22 (73.3%) patients and weak expression of nPARP in 8 (26.7%), whereas 5 (16.7%) patients showed cytoplasmic overexpression. On comparing expression of PARP with clinicopathological parameters, PARP overexpression was significantly associated with older population (age >50 years) (P = 0.002), postmenopausal women (P = 0.029), higher TNM stage (Stage II and III) (P = 0.014), higher histological grade (grade 2) (P = 0.043), and presence of lymphovascular invasion (P = 0.015). Enhanced PARP1 expression is closely correlated with positive estrogen receptor status (P = 0.001) and PR status (P = 0.001). Overall PARP and nPARP overexpression was significantly associated with ER- (P = 0.006 and P = 0.008) and PR-positive (P = 0.006 and P = 0.008) patients. The PARP and nPARP overexpression was significantly associated with nontriple-negative BC patients (P = 0.001 and P = 0.001). Conclusion: We have not come across any study in the literature to compare PARP expression in BC and BBD patients. On the basis of our observations, we concluded that PARP overexpression is a poor prognostic marker in BC.

Impact of COVID-19 outbreak on tropospheric NO2 pollution assessed using Satellite-ground perspectives observations in India.

The global outbreak of Novel Corona Virus 2019 (SARS-CoV-2) has made worldwide lockdown including India since March 24, 2020. The current research aims at the improvements of nitrogen dioxide (NO2) during the COVID-19 lockdown in India. This research has been done using both the open source data sets taken from satellite and ground based for better analysis. For the satellite-based analysis, the Sentinel 5 Precauser's Tropospheric NO2 from the European Space Agency and for the ground-based numeric data sets from Central Pollution Control Board (CPCB) has been used. During the COVID-19 disease, outbreak the world has set in quarantine and as an overcome air quality improved in Asian countries after national lockdown, the average NO2 rates plummeted calculated by 40-50%. Similarly, it dramatically decreased in Asia during the COVID-19 pandemic quarantine period. The basic statistical patterns of the NO2 concentration spectrum of historical data sets (2018-2020) bi-weekly showed during October to March were seen higher in each year. Related with National Ambient Air Quality Standards of mean of NO2 in India our result shown in the NO2 levels fall in 21 µg/m3 during the national lockdown, from the Central Pollution Control Board's air quality standards it almost decreased 50% of the hourly mean in India. This caused by the sudden restriction to the development of manufacturing and the transportations which ultimately minimized the fossil fuel burning which cause the most of the NO2 releases to the atmosphere. Nowadays, people are aware about comparatively prosperous future with clear blue skies and uses of renewable energy sources from the nature.

Detection of ESR1 mutations in circulating cell-free DNA from patients with metastatic breast cancer treated with palbociclib and letrozole.

ESR1 mutations are frequently acquired in hormone-resistant metastatic breast cancer (MBC). CDK4/6 inhibition along with endocrine therapy is a promising strategy in hormone receptor-positive MBC. However, the incidence and impact of ESR1 mutations on clinical outcome in patients treated with CDK4/6 inhibitors have not been defined. In this study, we evaluated the frequency of ESR1 mutations in cfDNA from 16 patients with MBC undergoing palbociclib and letrozole therapy. Four common ESR1 mutations (D538G, Y537C, Y537N, and Y537S) were analyzed in serial blood draws using ddPCR. Mutation rate was 31.3% (5/16) (n=3; de novo, n=2; acquired). D538G was the most frequent mutation (n=3), followed by Y537N and Y537S (n=2). One patient showed multiple ESR1 mutations. Mutations were enriched during therapy. Progression-free survival (PFS) and overall survival (OS) were similar in patients with and without mutation detected at any given time during treatment. However, PFS was significantly shorter in patients with ESR1 mutation at initial blood draw (3.3 versus 9.0 months, P-value=0.038). In conclusion, ESR1 mutation prevalence is consistent with recent studies in hormone-refractory breast cancer. Further, treatment with palbociclib and letrozole does not prevent selection of ESR1 mutations in later lines of therapy. Larger studies are warranted to validate these findings.

Effect of microneedles on transdermal permeation enhancement of amlodipine.

The present study aimed to investigate the effect of microneedle (MN) geometry parameters like length, density, shape and type on transdermal permeation enhancement of amlodipine (AMLO). Two types of MN devices viz. AdminPatch® arrays (ADM) (0.6, 1.2 and 1.5 mm lengths) and laboratory-fabricated polymeric MNs (PM) of 0.6 mm length were employed. In the case of PMs, arrays were applied thrice at different places within a 1.77-cm2 skin area (PM-3) to maintain the MN density closer to 0.6 mm ADM. Scaling analyses were done using dimensionless parameters like concentration of AMLO (Ct/Cs), thickness (h/L) and surface area of the skin (Sa/L2). Microinjection moulding technique was employed to fabricate PM. Histological studies revealed that the PM, owing to their geometry/design, formed wider and deeper microconduits when compared to ADM of similar length. Approximately 6.84- and 6.11-fold increase in the cumulative amount (48 h) of AMLO permeated was observed with 1.5 mm ADM and PM-3 treatments respectively, when compared to passive permeation amounts. Good correlations (R 2 > 0.89) were observed between different dimensionless parameters with scaling analyses. The enhancement in AMLO permeation was found to be in the order of 1.5 mm ADM ≥ PM-3 > 1.2 mm ADM > 0.6 mm ADM ≥PM-1 > passive. The study suggests that MN application enhances the AMLO transdermal permeation and the geometrical parameters of MNs play an important role in the degree of such enhancement.

Effect of Microneedle Type on Transdermal Permeation of Rizatriptan.

The present study was aimed to investigate the effect of salient microneedle (MN) geometry parameters like length, density, shape and type on transdermal permeation of rizatriptan (RIZ). Studies were carried out using two types of MN devices viz. AdminPatch® arrays (ADM) (0.6, 0.9, 1.2 and 1.5 mm lengths) and laboratory-fabricated polymeric MNs (PMs) of 0.6 mm length. In the case of the PMs, arrays were applied three times at different places within a 1.77-cm2 skin area (PM-3) to maintain the MN density closer to 0.6 mm ADM. Histological studies revealed that PM, owing to their geometry/design, formed wider and deeper microconduits when compared to ADM of similar length. Approximately 4.9- and 4.2-fold increases in the RIZ steady-state flux values were observed with 1.5 mm ADM and PM-3 applications when compared to the passive studies. A good correlation between different dimensionless parameters like the amount of RIZ permeated (C t /C s), thickness (h/L) and surface area (S a/L 2) of the skin was observed with scaling analyses. Numerical simulations provided further information regarding the distribution of RIZ in MN-treated skin after application of different MNs. Overall, the study suggests that MN application enhances the RIZ transdermal permeation and the geometrical parameters of MNs play an important role in the degree enhancement.

An Analysis of the Stress induced in the Periodontal Ligament during Extrusion and Rotation Movements- Part II: A Comparison of Linear vs Nonlinear FEM Study.

BACKGROUND: Optimal orthodontic forces are those which stimulate tooth movement with minimal biological trauma to the tooth, periodontal ligament (PDL) during and alveolar bone. Among various types of tooth movements, extrusion and rotational movements are seen to be associated with the least amount of root resorption and have not been studied in detail. The mechanical behavior of the PDL is known to be nonlinear elastic and thus a nonlinear simulation of the PDL provides precision to the calculated stress values. Therefore in this study, the stress patterns in the PDL were evaluated with extrusion and rotational movements using the nonlinear finite element method (FEM). MATERIALS AND METHODS: A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modelling software. Stresses in the PDL were evaluated with extrusive and rotational movements by a 3D FEM using ANSYS software with nonlinear material properties. RESULTS: It was observed that with the application of extrusive load, the tensile stresses were seen at the apex whereas the compressive stress was distributed at the cervical margin. With the application of rotational movements, maximum compressive stress was distributed at the apex and cervical third whereas the tensile stress was distributed on cervical third of the PDL on the lingual surface. CONCLUSION: For rotational and extrusion movements, stress values over the periodontal ligament was within the range of optimal stress value as proposed by Lee, with a given force system by Proffit as optimum forces for orthodontic tooth movement using nonlinear properties. During rotation there are stresses concentrated at the apex, hence due to the concentration of the compressive forces at the apex a clinician must avoid placing heavy stresses during tooth movement.

An Analysis of the Stress Induced in the Periodontal Ligament during Extrusion and Rotation Movements: A Finite Element Method Linear Study Part I.

BACKGROUND: Orthodontic tooth movement occurs due to various biomechanical changes in the periodontium. Forces within the optimal range yield maximum tooth movement with minimum deleterious effects. Among various types of tooth movements, extrusion and rotational movements are seen to be associated with the least amount of root resorption and have not been studied in detail. Therefore in this study, the stress patterns in the periodontal ligament (PDL) were evaluated with extrusion and rotational movements using the finite element method FEM. MATERIALS AND METHODS: A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modeling software. Stresses in the PDL were evaluated with extrusive and rotational movements by a 3D FEM using ANSYS software with linear material properties. RESULTS: It was observed that with the application of extrusive load, the tensile stresses were seen at the apex, whereas the compressive stress was distributed at the cervical margin. With the application of rotational movements, maximum compressive stress was distributed at the apex and cervical third, whereas the tensile stress was distributed on cervical third of the PDL on the lingual surface. CONCLUSION: For extrusive movements, stress values over the periodontal ligament was within the range of optimal stress value as proposed by Lee, with a given force system by Profitt as optimum forces for orthodontic tooth movement using linear properties. During rotation there are stresses concentrated at the apex, hence due to the concentration of the compressive forces at the apex a clinician must avoid placing heavy stresses during tooth movement.

Polarization screening-induced magnetic phase gradients at complex oxide interfaces.

Thin-film oxide heterostructures show great potential for use in spintronic memories, where electronic charge and spin are coupled to transport information. Here we use a La0.7Sr0.3MnO3 (LSMO)/PbZr0.2Ti0.8O3 (PZT) model system to explore how local variations in electronic and magnetic phases mediate this coupling. We present direct, local measurements of valence, ferroelectric polarization and magnetization, from which we map the phases at the LSMO/PZT interface. We combine these experimental results with electronic structure calculations to elucidate the microscopic interactions governing the interfacial response of this system. We observe a magnetic asymmetry at the LSMO/PZT interface that depends on the local PZT polarization and gives rise to gradients in local magnetic moments; this is associated with a metal-insulator transition at the interface, which results in significantly different charge-transfer screening lengths. This study establishes a framework to understand the fundamental asymmetries of magnetoelectric coupling in oxide heterostructures.

Ferroelectric polarization reversal via successive ferroelastic transitions.

Switchable polarization makes ferroelectrics a critical component in memories, actuators and electro-optic devices, and potential candidates for nanoelectronics. Although many studies of ferroelectric switching have been undertaken, much remains to be understood about switching in complex domain structures and in devices. In this work, a combination of thin-film epitaxy, macro- and nanoscale property and switching characterization, and molecular dynamics simulations are used to elucidate the nature of switching in PbZr(0.2)Ti(0.8)O3 thin films. Differences are demonstrated between (001)-/(101)- and (111)-oriented films, with the latter exhibiting complex, nanotwinned ferroelectric domain structures with high densities of 90° domain walls and considerably broadened switching characteristics. Molecular dynamics simulations predict both 180° (for (001)-/(101)-oriented films) and 90° multi-step switching (for (111)-oriented films) and these processes are subsequently observed in stroboscopic piezoresponse force microscopy. These results have implications for our understanding of ferroelectric switching and offer opportunities to change domain reversal speed.

Stationary domain wall contribution to enhanced ferroelectric susceptibility.

In ferroelectrics, the effect of domain wall motion on properties has been widely studied, but non-motional or stationary contributions from the volume of material within the domain wall itself has received less attention. Here we report the measurement of stationary domain wall contributions to permittivity in PbZr(0.2)Ti(0.8)O3 films. Studies of (001)-, (101)- and (111)-oriented epitaxial films reveal that (111)-oriented films, in which the motional domain wall contributions are frozen out, exhibit permittivity values approximately three times larger than the intrinsic response alone. This discrepancy can only be accounted for by considering a stationary contribution from the domain wall volume of the material that is 6-78 times larger than the bulk response, and is consistent with predictions of the enhancement of susceptibilities within 90° domain walls. This work offers new insights into the microscopic origin of dielectric enhancement and provides a pathway to engineer the dielectric response of materials.

Thickness-dependent crossover from charge- to strain-mediated magnetoelectric coupling in ferromagnetic/piezoelectric oxide heterostructures.

Magnetoelectric oxide heterostructures are proposed active layers for spintronic memory and logic devices, where information is conveyed through spin transport in the solid state. Incomplete theories of the coupling between local strain, charge, and magnetic order have limited their deployment into new information and communication technologies. In this study, we report direct, local measurements of strain- and charge-mediated magnetization changes in the La0.7Sr0.3MnO3/PbZr0.2Ti0.8O3 system using spatially resolved characterization techniques in both real and reciprocal space. Polarized neutron reflectometry reveals a graded magnetization that results from both local structural distortions and interfacial screening of bound surface charge from the adjacent ferroelectric. Density functional theory calculations support the experimental observation that strain locally suppresses the magnetization through a change in the Mn-eg orbital polarization. We suggest that this local coupling and magnetization suppression may be tuned by controlling the manganite and ferroelectric layer thicknesses, with direct implications for device applications.

Improved pyroelectric figures of merit in compositionally graded PbZr1-xTixO3 thin films.

Pyroelectric materials have been widely used for a range of thermal-related applications including thermal imaging/sensing, waste heat energy conversion, and electron emission. In general, the figures of merit for applications of pyroelectric materials are proportional to the pyroelectric coefficient and inversely proportional to the dielectric permittivity. In this context, we explore single-layer and compositionally graded PbZr1-xTixO3 thin-film heterostructures as a way to independently engineer the pyroelectric coefficient and dielectric permittivity of materials and increase overall performance. Compositional gradients in thin films are found to produce large strain gradients which generate large built-in potentials in the films that can reduce the permittivity while maintaining large pyroelectric response. Routes to enhance the figures of merit of pyroelectric materials by 3-12 times are reported, and comparisons to standard materials are made.

Differentiation of isolated and characterized human dental pulp stem cells and stem cells from human exfoliated deciduous teeth: An in vitro study.

AIMS AND OBJECTIVES: Isolation, characterization and differentiation of dental pulp stem cells (DPSCs) and stem cells from exfoliated human deciduous teeth (SHED). METHODS: The pulp tissue was digested in collagenase and cultured in DMEM Dulbecco's Modified Eagle's Media). The stem cells were identified and isolated. Surface characterization of cells was done with flow cytometer using surface markers. An immuno cytochemistry analysis was done. Differentiation potential was analyzed using various differentiation markers. RESULTS: Flow cytometry analyses for various CD markers showed similar results for both DPSCs and SHED. The cells showed positive expression for pluripotent, ectodermal and mesodermal markers. Cells differentiated into osteoblasts and adipocytes. CONCLUSION: The study demonstrated that stem cells existed in deciduous and permanent pulp tissue. The stem cells present in pulp tissue can be isolated, cultivated and expanded in vitro. Both DPSCs and SHED show almost a similar expression pattern profile for variety of antigens tested.

Effect of growth induced (non)stoichiometry on interfacial conductance in LaAlO3/SrTiO3.

We demonstrate a link between the growth process, the stoichiometry of LaAlO(3), and the interfacial electrical properties of LaAlO(3)/SrTiO(3) heterointerfaces. Varying the relative La:Al cation stoichiometry by a few atomic percent in films grown at 1×10(-3) Torr results in a 2 and 7 order-of-magnitude change in the 300 and 2 K sheet resistance, respectively, with highly conducting states occurring only in La-deficient or Al-excess films. Further reducing the growth pressure results in an increase of the carrier density and a dramatic change in mobility. We discuss the relative contributions of intrinsic and extrinsic effects in controlling the physical properties of this widely studied system.

Unexpected crystal and domain structures and properties in compositionally graded PbZr(1-x)Ti(x)O3 thin films.

Synthesis of compositionally graded versions of PbZr(1-x)Ti(x)O3 thin films results in unprecedented strains (as large as ≈4.5 × 10(5) m(-1)) and correspondingly unexpected crystal structures, ferroelectric domain structures, and properties. This includes the observation of built-in electric fields in films as large as 200 kV/cm. Compositional and strain gradients could represent a new direction of strain-control of materials.