Water Contact Angle Dependence with Hydroxyl Functional Groups on Silica Surfaces under CO₂ Sequestration Conditions

Functional groups on silica surfaces under CO₂ sequestration conditions are complex due to reactions among supercritical CO₂, brine and silica. Molecular dynamics simulations have been performed to investigate the effects of hydroxyl functional groups on wettability. It has been found that wettability shows a strong dependence on functional groups on silica surfaces: silanol number density, space distribution, and deprotonation/protonation degree. For neutral silica surfaces with crystalline structure (Q³, Q³/Q⁴, Q⁴), as silanol number density decreases, contact angle increases from 33.5° to 146.7° at 10.5 MPa and 318 K. When Q³ surface changes to an amorphous structure, water contact angle increases 20°. Water contact angle decreases about 12° when 9% of silanol groups on Q³ surface are deprotonated. When the deprotonation degree increases to 50%, water contact angle decreases to 0. The dependence of wettability on silica surface functional groups was used to analyze contact angle measurement ambiguity in literature. The composition of silica surfaces is complicated under CO₂ sequestration conditions, the results found in this study may help to better understand wettability of CO₂/brine/silica system

Hydrogen bonds at silica–CO₂ saturated water interface under geologic sequestration conditions

<p>To investigate the effects of sequestration condition on hydrogen bonds between mineral and water, molecular dynamics simulations have been performed. The simulations were conducted at conditions related with geologic sequestration sites: pressure (3.1–32.6 MPa), temperature (318 and 383 K), salinity (0–3 M), salt (NaCl and CaCl₂) and silica surface models Q² (geminal), Q³ (isolated) and amorphous Q³. The hydrogen bonds were classified into four types: silica–silica, silica–dissolved CO₂, silica–water as donors and silica–water as acceptors. The mean numbers of hydrogen bonds for each type were analysed. The results show that: (1) silica surface silanol groups do not form H-bonds with dissolved CO₂ molecules in water (brine); (2) The mean number of hydrogen bonds between silanol groups follows the order: Q² > amorphous Q³ > Q³; (3) The mean number of hydrogen bonds between silanol and water molecules follows the order: Q³ > amorphous Q³ > Q².</p

DataSheet_2_Assessment of new-onset heart failure prediction in a diabetic population using left ventricular global strain: a prospective cohort study based on UK Biobank.pdf

BackgroundImpaired glucose utilization influences myocardial contractile function. However, the prognostic importance of left ventricular global radial strain (LV-GRS), left ventricular global circumferential strain (LV-GCS), and left ventricular global longitudinal strain (LV-GLS) in predicting new-onset heart failure (HF) in a population with diabetes is unclear.MethodsThe study design is prospective cohort from the UK Biobank. Totally 37,899 participants had a complete data of cardiac magnetic resonance (CMR), of which 940 patients with diabetes were included, and all the participants completed follow-up. LV-GRS, LV-GCS, and LV-GLS were measured by completely automated CMR with tissue tagging. Cox proportional hazards regression analysis and C-index was performed to evaluate the association between the strain parameters and the new-onset HF in patients suffering from diabetes.ResultsThe average age of the 940 participants was 57.67 ± 6.97 years, with males comprising 66.4% of the overall population. With an average follow-up period of 166.82 ± 15.26 months, 35 (3.72%) patients reached the endpoint (emergence of new-onset HF). Significant associations were found for the three strain parameters and the new-onset HF (LV-GRS—hazard ratio [HR]: 0.946, 95% CI: 0.916-0.976; LV-GCS—HR: 1.162, 95% CI: 1.086-1.244; LV-GCS—HR: 1.181, 95% CI: 1.082-1.289). LV-GRS, LV-GCS, and LV-GLS were closely related to the related indicators to HF, and showed a high relationship to new-onset HF in individuals with diabetes at 5 and 10 years: LV-GRS: 0.75 (95% CI, 0.41-0.94) and 0.76 (95% CI, 0.44-0.98), respectively; LV-GCS: 0.80 (95% CI, 0.50-0.96) and 0.75 (95% CI, 0.41-0.98), respectively; LV-GLS: 0.72 (95% CI, 0.40-0.93) and 0.76 (95% CI, 0.48-0.97), respectively. In addition, age, sex, body mass index (BMI), and presence of hypertension or coronary artery disease (CAD) made no impacts on the association between the global strain parameters and the incidence of HF.ConclusionLV-GRS, LV-GCS, and LV-GLS is significantly related to new-onset HF in patients with diabetes at 5 and 10 years.</p

Adaptive Informational Design of Confirmatory Phase III Trials With an Uncertain Biomarker Effect to Improve the Probability of Success

<p>Oncology drug developers sometimes decide to initiate Phase III randomized confirmatory trials at risk after significant preliminary anti-tumor activities are observed in small Phase I/II single arm studies. There are two clear challenges. First, these investigational drugs may have a greater benefit in a biomarker enriched population. But the limited data from Phase I/II can hardly provide the much-needed information for selecting a biomarker cutpoint or prioritizing a biomarker hypothesis for Phase III testing. Second, the data seldom provide any insight on how the treatment benefit evolves over time. Risk-mitigation strategies such as conventional adaptive-designs that rely on interim analyses for modifying the study design are less reliable because the treatment effect observed at an interim analysis may not be the same as in the final analysis. The use of an intermediate endpoint for interim decision makes it even more unreliable because the predictive value of an intermediate endpoint is often unknown for drugs with a new mechanism of action. In this article, we present an alternative design strategy to mitigate the risks. The idea is to add an analysis of the primary endpoint at the end of the Phase III trial in a subgroup of patients representing the overall study population. We call it informational analysis and the corresponding design informational design to emphasize its difference from the conventional event-time or calendar-time-driven interim analysis. From a high-level perspective, the subgroup analysis is equivalent to a Phase II trial conducted under the same study design at the same time in the same population at the same sites as the Phase III trial. It provides a more reliable resource of information for inference than a separate Phase II trial or a conventional interim analysis. The strategy is applied to address a wide range of statistical issues encountered in expedited development of personalized medicines, including alpha splitting between a biomarker subpopulation and the overall population and de-selection of nonperforming biomarker subpopulations. Applications to hypothetical Phase III trials are illustrated. Although the strategy is motivated by oncology studies, it may be applied to drug development in other therapeutic areas with similar concerns. Supplementary materials for this article are available online.</p

DataSheet_1_Assessment of new-onset heart failure prediction in a diabetic population using left ventricular global strain: a prospective cohort study based on UK Biobank.csv

BackgroundImpaired glucose utilization influences myocardial contractile function. However, the prognostic importance of left ventricular global radial strain (LV-GRS), left ventricular global circumferential strain (LV-GCS), and left ventricular global longitudinal strain (LV-GLS) in predicting new-onset heart failure (HF) in a population with diabetes is unclear.MethodsThe study design is prospective cohort from the UK Biobank. Totally 37,899 participants had a complete data of cardiac magnetic resonance (CMR), of which 940 patients with diabetes were included, and all the participants completed follow-up. LV-GRS, LV-GCS, and LV-GLS were measured by completely automated CMR with tissue tagging. Cox proportional hazards regression analysis and C-index was performed to evaluate the association between the strain parameters and the new-onset HF in patients suffering from diabetes.ResultsThe average age of the 940 participants was 57.67 ± 6.97 years, with males comprising 66.4% of the overall population. With an average follow-up period of 166.82 ± 15.26 months, 35 (3.72%) patients reached the endpoint (emergence of new-onset HF). Significant associations were found for the three strain parameters and the new-onset HF (LV-GRS—hazard ratio [HR]: 0.946, 95% CI: 0.916-0.976; LV-GCS—HR: 1.162, 95% CI: 1.086-1.244; LV-GCS—HR: 1.181, 95% CI: 1.082-1.289). LV-GRS, LV-GCS, and LV-GLS were closely related to the related indicators to HF, and showed a high relationship to new-onset HF in individuals with diabetes at 5 and 10 years: LV-GRS: 0.75 (95% CI, 0.41-0.94) and 0.76 (95% CI, 0.44-0.98), respectively; LV-GCS: 0.80 (95% CI, 0.50-0.96) and 0.75 (95% CI, 0.41-0.98), respectively; LV-GLS: 0.72 (95% CI, 0.40-0.93) and 0.76 (95% CI, 0.48-0.97), respectively. In addition, age, sex, body mass index (BMI), and presence of hypertension or coronary artery disease (CAD) made no impacts on the association between the global strain parameters and the incidence of HF.ConclusionLV-GRS, LV-GCS, and LV-GLS is significantly related to new-onset HF in patients with diabetes at 5 and 10 years.</p

Summary ROC (SROC) curves for CTA and MRA.

<p>Summary ROC (SROC) curves for CTA and MRA.</p

Flowchart of study identification, inclusion, and exclusion.

<p>Flowchart of study identification, inclusion, and exclusion.</p

Wettability of Supercritical CO₂–Brine–Mineral: The Effects of Ion Type and Salinity

Deep saline aquifers are considered as perfect storage sites to sequestrate CO₂. Interfacial tensions (IFTs) and contact angles (CAs) are key parameters in the heat and mass transfer processes for CO₂/brine/mineral systems in porous media. In the present study, a molecular dynamics simulation method was used to investigate the effects of brine salinity and ion type on wettability of CO₂/brine/mineral systems at 20 MPa and 318.15 K. Four common brines were selected as NaCl, KCl, CaCl₂, and MgCl₂. Interfacial tensions, water contact angles, and hydrogen bond structure and dynamics have been analyzed. The effects of brine salinity and ion type on water contact angles were found to be very complicated. For MgCl₂ and NaCl solutions, the contact angle increases with salinity. For CaCl₂ and KCl solutions, contact angle first increases and then remains constant with salinity. The product of IFT­(CO₂–brine) and the cosine of CA was found to be constant for all brine solutions studied. In the context of large uncertainty of experimentally measured contact angles, this finding is very useful to predict contact angles using interfacial tension data. Due to the fact that IFT­(CO₂–brine) × cos­(CA) is usually related with capillary pressure and residual trapping capacity, this finding is also very helpful to predict these parameters at different brine conditions. More work is required to study the effects of pressure, temperature, and solid surface structure on this relationship

Table_1.XLSX

<p>Tuberculosis (TB) is a major comorbidity in HIV patients as well as a serious co-epidemic. Traditional detection methods are not effective or sensitive for the detection of Mycobacterium tuberculosis at the early stage. TB has become a major cause of lethal on HIV patients. We employed isobaric tags for relative and absolute quantitation (iTRAQ) technology to identify the different host responses in HIV-noTB and HIV-TB patients’ sera. Given the diversity of HIV subtypes, which results in a variety of host responses in different human populations, we focused on the Chinese patients. Of the 25 proteins identified, 7 were increased and 18 were decreased in HIV-TB co-infected patients. These proteins were found to be involved in host immune response processes. We identified a candidate protein, endoglin (ENG), which showed an 4.9 times increase by iTRAQ and 11.5 times increase by ELISA. ENG demonstrated the diagnostic efficacy and presented a novel molecular biomarker for TB in HIV-infected Chinese patients. This study provides new insight into the challenges in the diagnosis and effective management of patients with HIV-TB.</p

Pressure and Temperature Dependence of Contact Angles for CO₂/Water/Silica Systems Predicted by Molecular Dynamics Simulations

Wettability controls the capillary behavior of injected CO₂, including capillary entry pressure, relative permeability, and residual fluid saturation, and it is one of the most active topics in geologic carbon sequestration (GCS). However, the large uncertainty of water contact angle (CA) data and its pressure, temperature, and salinity dependence in the literature limit our understanding on wettability. Molecular dynamics (MD) simulations have been performed to investigate the pressure (<i>P</i>) and temperature (<i>T</i>) dependence of water CAs on the silica surface. Three typical molecular surface models for silica, namely, Q², crystalline Q³, and amorphous Q³, were selected, and simulations were conducted at wide pressure (2.8–32.6 MPa) and temperature (318–383 K) conditions. The results show that <i>P</i> and <i>T</i> dependence of water CAs on silica surfaces is controlled by surface functional groups. These findings provide new information to help with the better understanding of wettability alteration under different GCS conditions