Interaction between Sulfated Zirconia and Alkanes: Prerequisites for Active Sites – Formation and Stability of Reaction Intermediates

Two sulfated zirconia catalysts were prepared via sulfation and calcination at 873 K of zirconium hydroxide aged at room temperature for 1 h (SZ-1) or aged at 373 K for 24 h (SZ-2). SZ-1 was active for n-butane isomerisation at 373 K; SZ-2 reached similar performance only at 473 K. Both materials contained about 9 wt% sulfate and were tetragonal. Due to a BET lower surface area (105 m2/g vs. 148 m2/g) SZ-1 featured a higher sulfate density, and XRD and EXAFS analysis showed larger (ca. 10 nm) and more well ordered crystals than for SZ-2. n-Butane TPD on SZ-1 showed a butene desorption peak at low temperature, whereas, no obvious butene desorption was observed with SZ-2, suggesting that SZ-1 has a higher oxidizing power at low temperature than SZ-2. The number of sites capable of dehydrogenation are less than 5 µmol/g, because the differential heats of n-butane adsorption as measured by microcalorimetry were 45–60 kJ/mol for higher coverages, indicating weak and reversible interaction. TAP experiments describe the adsorption and desorption behavior of n-butane at different activity states and are the basis for a simple adsorption model. Reactant pulses and purge experiments show that the active species, presumably formed in an oxidative dehydrogenation step, are stable at the surface under reaction conditions

Structural and Active Site Characterization of Sulfated Zirconia Catalysts for Light Alkane Isomerization

Two different sulfated zirconia catalysts were produced through precipitation from zirconyl nitrate solutions, followed by aging of the precipitate either at 298 K for 1 h (SZ-1) or 373 K for 24 h (SZ-2). After drying, the samples were sulfated with ammonium sulfate and calcined for 3 h at 873 K. SZ-1 had a smaller surface area (90 m2 g-1) than SZ-2 (140 m2 g-1) but displayed a one order of magnitude higher maximum n-butane isomerization rate (373–423 K, 1–5 kPa n-butane at 101.3 kPa total pressure). Both materials consisted predominantly of tetragonal ZrO2, contained 9 wt% of sulfate, and adsorbed about 0.5 mmol g-1 NH3. Measurements of adsorption isotherms and differential heats for propane and iso-butane at 313 K reveal a larger number of adsorption sites on SZ-1 than on SZ-2, extrapolated to 1 kPa, 42 vs. 20 µmol g-1 (propane) and 120 vs. 44 µmol g-1 (iso-butane). At coverages > 2 µmol g-1 the heats were similar for both samples with both probes and decreased from 60 to 40 kJ mol-1. Temporal analysis of products measurements indicated shorter residence times for n-butane than for iso-butane, and SZ-1 retained both of these molecules longer than SZ-2. The activation energy for n-butane desorption was 45 kJ mol-1 for both samples. Interaction with pulses of CO2 suggested that non-sulfated, basic ZrO2 surface is exposed on SZ-2, consistent with the larger surface area at the same sulfate content as SZ-1. The results suggest that only a fraction of the sulfate groups participates in adsorption and that product desorption may be of importance

Structural and Active Site Characterization of Sulfated Zirconia Catalysts for Light Alkane Isomerization

Sulfated zirconia (SZ) is active for light alkane isomerization at temperatures as low as 373 K [1]. The material has been investigated extensively in the past 2 decades [2] but so far no convincing structure-activity relationship has been established. Here, we report on the investigation of two different SZ materials with an interesting combination of properties. Both materials have a sulfate content of 9 wt.%; however, the material with lower specific surface area (SZ-1, 90 m2og-1) displays a maximum n-butane isomerization rate (373-423 K, 1-5 kPa n-butane at 101.3 kPa total pressure) that is about one order of magnitude higher than that of the material with higher specific surface area (SZ-2, 140 m2og-1). Both materials were produced through precipitation from zirconyl nitrate solution, followed by aging of the precipitate either at 298 K for 1 h (SZ-1) or 373 K for 24 h (SZ-2). After drying, the samples were sulfated with ammonium sulfate and calcined for 3 h at 873 K. Scanning electron microscopy showed typical particle sizes of 5 to 20 µm for SZ-1, and of 1 to 5 µm for SZ-2. X-ray diffraction and Zr K-edge X-ray absorption spectra identified both materials as predominantly tetragonal ZrO2, but SZ-2 exhibited smaller crystalline domains than SZ-1 (7.5 vs. 10 nm). Diffuse reflectance IR spectra taken during catalyst activation (523 K, inert gas) suggest that the sulfate structures on the two materials rearrange in a slightly different way during dehydration. This is tentatively attributed to different sulfate group densities that result from the ratios of sulfate content to surface area. By ammonia adsorption/desorption, the concentration of acid sites was determined to be 0.52 and 0.48 mmolog-1 for SZ-1 and SZ-2, respectively; this result is not reflected by the catalytic activities. Temporal analysis of products measurements indicated that the residence times for n-butane were shorter than for i-butane, and SZ-1 retained both these molecules longer than SZ-2. The activation energy for n-butane desorption was equivalent for both samples, i.e., 40-41 kJomol-1. Calorimetric measurements of the adsorption of reactant and product at 313 K produced the following results. At 0.3 kPa alkane pressure, SZ-1 and SZ-2 adsorbed similar amounts of n-butane (20 and 25 µmol), but very different amounts of i-butane (80 and 25 µmol). At coverages below 2 µmol the differential heats of adsorption of n-butane were much higher on SZ-2 than on SZ-1, while at higher coverages the heats were nearly identical for both samples and decreased from 60 to 40 kJomol-1. The samples did not differ with respect to the strength of interaction with i-butane, the heats decreased with increasing coverage from 60 to 40 kJomol-1. The results demonstrate that (i) typical SZ catalysts have fewer than 100 µmolog-1 sites, rendering identification by spectroscopic techniques difficult, and (ii) product desorption is a critical factor for the catalytic performance. References: [1] M. Hino, K. Arata, J. Chem. Soc. Chem. Comm. (1980) 851. [2] X. Song, A. Sayari, Catal. Rev. Sci. Eng., 38 (1996) 32

Dutch translation and cultural adaptation of new LYMPH-Q- scales measuring impact on work and lymphedema worry

Background: Breast cancer-related lymphedema (BCRL) is a significant complication of breast cancer treatment that can impact patients’ quality of life. This study focuses on the translation and cultural adaptation of two new LYMPH-Q scales ‘Impact on Work’ and ‘Lymphedema worry’ into Dutch to assess the work-related challenges and worries experienced by patients with BCRL in the Netherlands. Methods: The translation process followed established guidelines from the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) and the World Health Organization (WHO). Forward and back translations, expert panel reviews, cognitive debriefing interviews with patients with BCRL, and proofreading were conducted to refine the Dutch translation of the scales. The translation aimed to ensure conceptual equivalence and cultural relevance. Results: The translation process resulted in the Dutch versions of the LYMPH-Q ‘Impact on Work’ and ‘Lymphedema worry’ scales. The forward translation revealed discrepancies in meaning, word order and synonyms. The back translation and review resulted in changes in item formulation. The expert panel meeting and cognitive debriefing interviews provided valuable input for further refinement. Conclusion: The translated LYMPH-Q ‘Impact on Work’ and ‘Lymphedema worry’ scales provide healthcare professionals with an instrument to assess and monitor the impact of BCRL on work-related challenges and on worries. This comprehensive translation process, involving patients with BCRL and experts, ensured the linguistic accuracy, cultural relevance, and clarity of the Dutch versions. The translated scales will contribute to a better understanding of the multifaceted impact of BCRL and facilitate the development of tailored interventions to improve patients’ well-being and functional outcomes.</p

Dutch translation and cultural adaptation of new LYMPH-Q- scales measuring impact on work and lymphedema worry

Background: Breast cancer-related lymphedema (BCRL) is a significant complication of breast cancer treatment that can impact patients’ quality of life. This study focuses on the translation and cultural adaptation of two new LYMPH-Q scales ‘Impact on Work’ and ‘Lymphedema worry’ into Dutch to assess the work-related challenges and worries experienced by patients with BCRL in the Netherlands. Methods: The translation process followed established guidelines from the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) and the World Health Organization (WHO). Forward and back translations, expert panel reviews, cognitive debriefing interviews with patients with BCRL, and proofreading were conducted to refine the Dutch translation of the scales. The translation aimed to ensure conceptual equivalence and cultural relevance. Results: The translation process resulted in the Dutch versions of the LYMPH-Q ‘Impact on Work’ and ‘Lymphedema worry’ scales. The forward translation revealed discrepancies in meaning, word order and synonyms. The back translation and review resulted in changes in item formulation. The expert panel meeting and cognitive debriefing interviews provided valuable input for further refinement. Conclusion: The translated LYMPH-Q ‘Impact on Work’ and ‘Lymphedema worry’ scales provide healthcare professionals with an instrument to assess and monitor the impact of BCRL on work-related challenges and on worries. This comprehensive translation process, involving patients with BCRL and experts, ensured the linguistic accuracy, cultural relevance, and clarity of the Dutch versions. The translated scales will contribute to a better understanding of the multifaceted impact of BCRL and facilitate the development of tailored interventions to improve patients’ well-being and functional outcomes.</p

Hair Follicle Mesenchyme-Associated PD-L1 Regulates T-Cell Activation Induced Apoptosis: A Potential Mechanism of Immune Privilege

The immune privilege (IP) of hair follicles (HFs) has been well established in previous studies. However, whether cultured HF cells still exhibit IP properties, the individual factors involved in this process, and the detailed mechanisms that drive and maintain IP, are largely unidentified. We found preferential expression of IP-associated genes in cultured HF dermal papilla and dermal sheath cup cells (DSCCs) compared with non-follicular fibroblasts (FBs) at passage 4, suggesting a potential for functional IP. Notably, programmed cell death 1 ligand 1 (PD-L1) was significantly upregulated in DSCCs and dermal papilla cells relative to FBs. IFNγ secretion from peripheral blood mononuclear cells (PBMCs) co-cultured with histoincompatible DSCCs was significantly lower than with FB and higher percentages of early apoptotic, Annexin V+ cells were observed in PBMC co-cultured with DSCCs. Knockdown of PD-L1 translation by silencing interfering RNA in DSCCs enabled increased IFNγ secretion by PBMCs, whereas transfection of pCMV6-XL4/hPD-L1 in FB significantly reduced IFNγ secretion and increased apoptosis in co-cultured PBMCs. We also found that apoptosis in allogeneic T cells induced by DSCCs was largely dependent on the mitochondrial pathway. Our study suggests IP properties are exhibited in cultured DSCCs in part through expression of negative co-signaling molecule PD-L1

Hair Follicle Dermal Sheath Derived Cells Improve Islet Allograft Survival without Systemic Immunosuppression

Immunosuppressive drugs successfully prevent rejection of islet allografts in the treatment of type I diabetes. However, the drugs also suppress systemic immunity increasing the risk of opportunistic infection and cancer development in allograft recipients. In this study, we investigated a new treatment for autoimmune diabetes using naturally immune privileged, hair follicle derived, autologous cells to provide localized immune protection of islet allotransplants. Islets from Balb/c mouse donors were cotransplanted with syngeneic hair follicle dermal sheath cup cells (DSCC, group 1) or fibroblasts (FB, group 2) under the kidney capsule of immune-competent, streptozotocin induced, diabetic C57BL/6 recipients. Group 1 allografts survived significantly longer than group 2 (32.2 ± 12.2 versus 14.1 ± 3.3 days, P<0.001) without administration of any systemic immunosuppressive agents. DSCC reduced T cell activation in the renal lymph node, prevented graft infiltrates, modulated inflammatory chemokine and cytokine profiles, and preserved better beta cell function in the islet allografts, but no systemic immunosuppression was observed. In summary, DSCC prolong islet allograft survival without systemic immunosuppression by local modulation of alloimmune responses, enhancing of beta cell survival, and promoting of graft revascularization. This novel finding demonstrates the capacity of easily accessible hair follicle cells to be used as local immunosuppression agents in islet transplantation

A Cross-Sectional Study of HPV Vaccine Acceptability in Gaborone, Botswana

Background Cervical cancer is the most common cancer among women in Botswana and elsewhere in Sub-Saharan Africa. We sought to examine whether HPV vaccine is acceptable among parents in Botswana, which recently licensed the vaccine to prevent cervical cancer. Methods and Findings We conducted a cross-sectional survey in 2009, around the time the vaccine was first licensed, with adults recruited in general medicine and HIV clinics in Gaborone, the capital of Botswana. Although only 9% (32/376) of respondents had heard of HPV vaccine prior to the survey, 88% (329/376) said they definitely will have their adolescent daughters receive HPV vaccine. Most respondents would get the vaccine for their daughters at a public or community clinic (42%) or a gynecology or obstetrician\u27s office (39%), and 74% would get it for a daughter if it were available at her school. Respondents were more likely to say that they definitely will get HPV vaccine for their daughters if they had less education (OR = 0.20, 95% CI = 0.07–0.58) or lived more than 30 kilometers from the capital, Gaborone (OR = 2.29, 95% CI = 1.06–4.93). Other correlates of acceptability were expecting to be involved in the decision to get HPV vaccine, thinking the vaccine would be hard to obtain, and perceiving greater severity of HPV-related diseases. Conclusions HPV vaccination of adolescent girls would be highly acceptable if the vaccine became widely available to the daughters of healthcare seeking parents in Gaborone, Botswana. Potential HPV vaccination campaigns should provide more information about HPV and the vaccine as well as work to minimize barriers

Health Locus of Control and Assimilation of Cervical Cancer Information in Deaf Women

This study assessed the relationship between Deaf women's internal health locus of control (IHLC) and their cervical cancer knowledge acquisition and retention. A blind, randomized trial evaluated Deaf women's (N = 130) baseline cancer knowledge and knowledge gained and retained from an educational intervention, in relation to their IHLC. The Multidimensional Health Locus of Control scales measured baseline IHLC, and a cervical cancer knowledge survey evaluated baseline to post-intervention knowledge change. Women's IHLC did not significantly predict greater cervical cancer knowledge at baseline or over time. IHLC does not appear to be a characteristic that must be considered when creating Deaf women's cancer education programs