53 research outputs found
Opioid Prescribing Guidelines in Breast Surgery: A Systematic Review
No full textA systematic review focusing on evaluating current guidance surrounding opioid prescribing in breast surgery. Primary outcomes include opioid specific guidance. Secondary outcomes include advice regarding other analgesic adjuncts, and education surrounding opioid use
Mass spectrometry imaging of protein distribution on biological tissue surface(s)
No full textPh.D.This thesis reports the development of a protein mass spectrometry imaging (MSI) workflow for animal tissue sections using membrane funnel-based spray ionization technique. The project was divided into three phases. The first phase was to validate the analytical performance of in situ clean-up and phosphopeptides selective enrichment using TᵢO₂-attached membrane funnel. The procedures were optimized using mixtures of non-phosphorylated peptides and phosphopeptides standards. To increase the elution efficiency and to lower the detection limit, an alkaline soaking step was developed. Using mixture of in-solution tryptic digest of horse myoglobin, mono- and tri-phosphorylated peptides standards to mimic real biological sample, detection limit, linearity and reproducibility of the optimized protocol were evaluated. The detection limits of mono- and tri-phosphorylated peptides were 50 and 500 fmol, respectively. The second phase was to investigate the feasibility of using C₁₈- and TᵢO₂-attached membrane funnel-based spray ionization platform for in-funnel digestion of proteins. In-funnel digestion protocol without reductive alkylation was developed with bovine β-casein – a simple protein standard. A mono-phosphorylated peptide was spiked as internal standard to the funnels prior to mass spectrometry analysis. Adopting the method of internal standard could reduce the influence experimental factors, such as spray stability and ion transmission efficiency; and improve the linearity of the developed method. In-funnel digestion protocol with reductive alkylation was also developed for proteins with disulphide bonds. Comparing with in-solution digest, the sequence coverage of in-funnel digest of ovalbumin with one disulphide linkage and ovocystatin with two disulphide linkages increased from 36% to 65% and from 21% to 81%, respectively. A protein loading as low as 100 fmol ovalbumin was found to be enough to provide detectable tryptic peptide ions on C₁₈-attached funnels. It was intriguing to note that one of the two expected phosphopeptides of ovalbumin and both expected phosphopeptides of ovocystatin were detected from digests in C₁₈-attached funnels rather than that of TᵢO₂-attached funnels. Some non-phosphorylated peptides of ovalbumin were also detected in TᵢO₂-attached funnels, too. It was therefore believed that hydrophobic C₁₈-attached funnels and hydrophilic TᵢO₂-attached funnels have complimentary nature in the peptides retention and detection. The developed protocols were applied to the analysis of diluted crude bovine milk – an example of complex biological protein mixture using C₁₈- and TᵢO₂-attached membrane funnels. Tryptic peptides were detected; and major proteins were identified with reasonable sequence coverages. The third phase was to apply the membrane funnel-based spray ionization technique to MSI analysis. New set-up was designed and fabricated to alleviate the alignment difficulties as in the previous set-up1. Identification of proteins in the mouse liver protein extract was obtained using in-solution digestion followed by LC-MS/MS analysis. Tissue imprinting method for transferring proteins from sections of mouse liver tissue to membrane funnels was developed. The tissue sections were separately imprinted onto the arrays of C₁₈- and TᵢO₂-attached membrane funnels, and the transferred proteins in each funnel were digested. Tryptic peptides were enriched and detected, and the distribution of several characteristic proteins could be obtained from the images of the peptide distributions. By analyzing the tissue sections using both hydrophobic and hydrophilic sorbent-attached membrane funnels, a more complete picture of the protein distribution could be obtained.本研究重點在於及開發一個利用微孔膜電噴霧電離源做動物組織切片裏蛋白質質譜成像的實驗流程。研究分為三個階段，第一階段是驗證磷酸肽在二氧化鈦修飾的膜微孔上原位純化和選擇性富集的分析性能，首先利用非磷酸化肽和磷酸肽的標準樣混合物優化實驗步驟。為了提升洗脫效能和降低偵測極限，我們開發了一個鹼性浸泡步驟。我們利用馬肌紅蛋白降解樣本、单磷酸肽標準樣和三磷酸肽標準樣的混合物模仿真實的生物樣本，然後評估優化技術的偵測極限、線性關係和再現性。单磷酸肽和三磷酸肽的偵測極限分別為50和500皮摩爾。第二階段研究是探討在C₁₈和二氧化鈦修飾的膜微孔上進行原位蛋白降解的可行性。首先利用一個簡單的標準蛋白樣 – 牛β酪蛋白開發不含還原烷化作用的膜微孔原位蛋白降解方法，我們於進行質譜分析前在每一個膜微孔上加了单磷酸肽標準樣作為內標準品，可以減少實驗環境因素，例如電噴霧的穩定性和離子傳輸效率的影響和提高線性度。下一步是開發含還原烷化作用的膜微孔原位蛋白降解方法，用於帶有雙硫鍵的蛋白，結果顯示卵清蛋白透過膜微孔原位蛋白降解的肽段覆蓋率比蛋白溶液降解由36%提升至65%，而卵胱抑素的肽段覆蓋率亦由21%提升至81%。這個方法只需要低至100皮摩爾的卵清蛋白就能在C₁₈修飾的膜微孔上產生探測到的由胰蛋白酶降解的肽。有趣的是，兩條卵清蛋白的磷酸肽中的其中一條和兩條卵胱抑素的磷酸肽只在C₁₈修飾的膜微孔上檢測到，此外，在二氧化鈦修飾的膜微孔上亦檢測到獨有的非磷酸化肽，我們認為由於C₁₈修飾的膜微孔是疏水性的，而二氧化鈦修飾的膜微孔是親水性，因此從兩種不同修飾的膜微孔中檢測到的肽會有互補效果。我們將以上的方法應用於複雜生物樣本 – 牛奶，牛奶中的蛋白成功在C₁₈和二氧化鈦修飾的膜微孔上進行蛋白降解，亦成功檢測到由胰蛋白酶降解的肽，得到合理的肽段覆蓋率。第三階段研究將微孔膜電噴霧電離源技術應用於質譜成像實驗中。我們重新設計及製作微孔膜電噴霧電離源裝置以解決現有裝置在質譜成像實驗難以對準位置的問題。老鼠肝中提取的蛋白透過液相層析串聯質譜方法鑑定。另外，我們開發了在修飾的膜微孔矩陣上製造生物組織印記的方法，並應用於製作老鼠肝印記，轉移到修飾的膜微孔的蛋白會被降解，然後我們富集和以質譜成像方式檢測由胰蛋白酶降解的肽，以此得到幾種蛋白在老鼠肝橫切面上的分佈，透過使用兩種不同修飾的膜微孔進行質譜成像實驗，我們可以得到更全面的蛋白分佈資訊。Hung, Yik Ling.Thesis Ph.D. Chinese University of Hong Kong 2020.Includes bibliographical references (leaves 177-204).Abstracts also in Chinese.Title from PDF title page (viewed on February 16, 2022)
Probabilistic risk assessment of the energy saving shortfall in energy performance contracting projects–a case study
No full textAuthor name used in this manuscript: P.T.I. LamAuthor name used in this manuscript: F.W.H. YikAuthor name used in this manuscript: E.H.W. Chan2013-2014 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishedGreen (AAM
Symptomatic venous thromboembolism in Chinese patients after gynecologic surgery: incidence and disease pattern
No full text
Author Correction: Transcript expression-aware annotation improves rare variant interpretation
No full textIn this Article, author Marquis P. Vawter was missing from the Genome Aggregation Database Consortium list. They are associated with the affiliation: ‘Department of Psychiatry & Human Behavior, University of California Irvine, Irvine, CA, USA’, and contributed to the generation of the primary data incorporated into the gnomAD resource. The original Article has been corrected online
Work-Family Conflict and Facilitation among Employees in Hong Kong
No full textWork-family imbalance can induce negative consequences, such as poor physical and psychological well-being for individuals. Hong Kong employees commonly agree that work-family balance is important for them, but it is difficult to balance work and family lives (Mahtani, 2006). Very few studies have comprehensively explored how to eliminate the conflict, and to enhance the integration between work and family domains. This may hinder researchers and practitioners from exploring effective strategies for promoting work-family balance. The present study explored work-family conflict and enrichment among Hong Kong employees.
This study examined the relationships between demands and resources in work and family lives, work-family conflict and enrichment, personal and work outcomes, and optimism and Confucian work values as moderator variables. The longitudinal mediating effects of work-family conflict and enrichment were examined, and potential cross-sectional and longitudinal moderating effects on the relationships between predictor variables and work-family conflict and enrichment were also explored.
A two-wave panel design was adopted with data collection separated by a ten-month interval. Questionnaires were designed for the participants and their supervisors. 509 participants at Time 1 and 208 participants at Time 2 from three universities in Hong Kong completed self-report questionnaires, and 208 supervisors of the participants completed another questionnaire at Time 2.
Predictor variables at work were significantly associated with work-family conflict and enrichment perceived in the work domain, and predictor variables in the family domain were significantly related to work-family conflict and enrichment perceived in the family domain. Work-family conflict and enrichment were significantly associated with personal and work outcomes.
Mediation analyses showed that there were very few longitudinal mediating effects of work-family conflict and enrichment between predictor and criterion variables. These findings suggest that work-family conflict and enrichment might not consistently contribute mediating effects in the relationships between these predictor and criterion variables over time.
Potential effects of optimism and Confucian work values have been rarely explored in previous Chinese work-family studies, and therefore this study examined the moderating effects of these two variables in relation to work-family conflict and enrichment. However, moderating analyses indicated that there were very few cross-sectional and longitudinal moderating effects of optimism and Confucian work values confirmed in this study.
Overall, the findings of this research illustrate that work-family conflict and enrichment could be separately affected by demands and resources in work and family lives. Work-family conflict and enrichment could also contribute significant effects on individuals’ well-being and work productivity. The results also imply that the significance of mediation and moderation effects for work-family conflict and enrichment might be determined by personal factors (e.g. coping strategies of individuals) or organisational factors (e.g. organisational culture).
The present study separately examined two directions of work-family conflict and enrichment, which extends the understanding of these topics in the Chinese context. The findings support related Western literature that perceived work-family conflict and enrichment in one domain were determined by the source in the same domain, and each direction of conflict or enrichment was associated with outcomes in the domain receiving the conflict or enrichment. These findings may extend the discussion of the relationships between potential factors and consequences of work-family conflict and enrichment for Hong Kong employees. The present study also provided additional information to understand the relationships between cultural values and work-family conflict and enrichment. The results may aid practitioners to formulate appropriate interventions, such as family-friendly employment policies and practices in enhancing work-family balance in Hong Kong
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