| 1. |
- Caldararu, Octav, et al.
(författare)
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QM/MM study of the reaction mechanism of sulfite oxidase
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Sulfite oxidase is a mononuclear molybdenum enzyme that oxidises sulfite to sulfate in many organisms, including man. Three different reaction mechanisms have been suggested, based on experimental and computational studies. Here, we study all three with combined quantum mechanical (QM) and molecular mechanical (QM/MM) methods, including calculations with large basis sets, very large QM regions (803 atoms) and QM/MM free-energy perturbations. Our results show that the enzyme is set up to follow a mechanism in which the sulfur atom of the sulfite substrate reacts directly with the equatorial oxo ligand of the Mo ion, forming a Mo-bound sulfate product, which dissociates in the second step. The first step is rate limiting, with a barrier of 39-49 kJ/mol. The low barrier is obtained by an intricate hydrogen-bond network around the substrate, which is preserved during the reaction. This network favours the deprotonated substrate and disfavours the other two reaction mechanisms. We have studied the reaction with both an oxidised and a reduced form of the molybdopterin ligand and quantum-refinement calculations indicate that it is in the normal reduced tetrahydro form in this protein.
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| 2. |
- Rydé, Kerstin, et al.
(författare)
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Crying : A force to balance emotions among cancer patients in palliative home care
- 2007
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Ingår i: Palliative & Supportive Care. - : Cambridge University Press. - 1478-9515 .- 1478-9523. ; 5:1, s. 51-59
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Crying is a common but seldom studied phenomenon in palliative care. The aim of this study was to explore the significance of patients crying in a palliative care context.Methods: Tape-recorded interviews with 14 cancer patients in palliative home care were carried out. To gain deeper understanding, a hermeneutic analysis and interpretation was used.Results: Crying was described in different dimensions: (1) intense and despondent crying as a way of ventilating urgent needs, (2) gentle, sorrowful crying as a conscious release of emotions, and (3) quiet, tearless crying as a protection strategy. Crying seems to be an expression for an inner emotional force, provoked by different factors, which cause changes in the present balance. To cry openly but also to cry on the inside meant being able to achieve or maintain balance. Crying may be something useful, which could create release and help reduce tension, but it may also have a negative impact as it consumes energy and creates feelings of shame.Significance of results: Professionals need to understand the different levels of crying. In such situations sometimes comforting the patient may not be the best solution, as some may need privacy.
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| 3. |
- Rydé, Kerstin, et al.
(författare)
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Crying in solitude or with someone for support and consolation - experiences from family members in palliative home care
- 2008
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Ingår i: Cancer Nursing. - 0162-220X .- 1538-9804. ; 31:5, s. 345-353
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Tidskriftsartikel (refereegranskat)abstract
- Crying has not been studied from the perspective of family members of patients in palliative care. The aim of this study was to explore the significance of family members crying in a palliative care context with special reference to factors that influence crying. Interviews were carried out with 14 family members of patients admitted to palliative care. A hermeneutic approach according to Gadamer was used. Three main categories emerged. (1) Before the start of crying, some prerequisites for crying had to be fulfilled, such as an allowing attitude and courage, time, feeling secure, honesty, and trusting relationships. These prerequisites did not cause crying themselves; rather crying emerged when triggering factors occurred. (2) Triggers for crying were circumstances that created uncertainty and turbulence (bad news), exhaustion due to lack of own time, and sympathy from others. (3) Family members tried to do the best possible by adopting or hiding their crying, to ease the patient's burden and to create a positive counterbalance to suffering and grief. As an interpretation of the whole, crying could be expressed as being shared with someone for support and consolation or escape to solitude for integrity and respite. As a conclusion, crying may be an efficient strategy for family members in palliative care to express their suffering and to gain new energy to continue.
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| 4. |
- Rydé, Kerstin, 1959-
(författare)
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Gråtens betydelse för patienter och närstående i palliativ hemsjukvård
- 2007
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- AbstraktGråt är vanlig bland patienter och närstående men sällan studerat i palliativ vård. Gråten kan vara ett sätt för patienter och deras närstående att uttrycka sorg och hantera en situation fylld av stress som är orsakad av förluster, många allvarliga symtom och en nära förestående död.Studiernas övergripande syfte var att bidra till en djupare förståelse för vilken betydelse gråten har för patienter och deras närstående i palliativ hemsjukvård: Vad innebär gråten och hur påverkar den de berörda? Bandinspelade intervjuer gjordes med 14 patienter med cancersjukdom och 14 närstående i palliativ hemsjukvård. För att få en djupare förståelse genomfördes arbetet med ett hermeneutiskt metodologiskt angreppssätt enligt Gadamer.Resultatet visade att patienterna (studie I) beskrev olika dimensioner och funktioner av gråt; Intensiv och förtvivlad gråt för att ge uttryck för akuta behov: Stilla och sorgsen gråt som medvetet förlöste känslor; Tyst och tårlös gråt som en skyddande strategi. Som en tolkning av helheten sågs patienternas gråt (studie I) som ett sätt att uttrycka en inre känslomässig kraft, framkallad av olika faktorer, som orsakade förändringar i den nuvarande inre balansen. Genom att gråta öppet men också inombords skapades eller upprätthölls balansen. Studie (II) visade att de närstående upplevde att gråten var beroende av olika förutsättningar som attityder och mod, tid, trygghet, ärliga och tillitsfulla relationer. Omskakande och oroande händelser, utmattning i brist på egen tid och sympati från andra var omständigheter som utlöste gråten. De närstående försökte göra det bästa möjliga för patienten genom att anpassa eller dölja gråten, allt för att underlätta bördan och skapa en positiv motvikt till lidande och sorg. Tolkningen av helheten (studie II); närståendes gråt kunde vara ett uttryck för att dela något tillsammans för gemenskap, tröst och stöd eller att söka sig till ensamhet för enskildhet och återhämtning.Sammanfattningsvis kan gråten ses som en copingstrategi eftersom den reducerar spänningar och skapar befrielse, upprätthåller balans, ger tröst, ny energi och tillfällen för enskildhet. Det är ett sätt att uttrycka lidande men på samma gång kräver gråten energi och ger känslor av skam.En viktig del i professionens arbete bör därför vara att tillåta gråten, lyssna, vara närvarande, uppmuntra uttryck av känslor men också ge utrymme för enskildhet. Läkaren, sjuksköterskan och andra i teamet kan lindra patientens och närståendes känslor av skam och sårbarhet genom att bekräfta, legitimera olika uttryck för gråt och därmed skapa en tolerant, säker och trygg omgivning.
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| 5. |
- Rydé, Kerstin, et al.
(författare)
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How to support patients who are crying in palliative home care : an interview study from the nurses' perspective.
- 2016
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Ingår i: Primary Health Care Research and Development. - : Cambridge University Press. - 1463-4236 .- 1477-1128. ; 17:5, s. 479-488
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Tidskriftsartikel (refereegranskat)abstract
- Aim The aim of this study was to explore how nurses can support patients who are crying in a palliative home care context.BACKGROUND: In palliative care the nurse has a central role in the team whose duty it is to create a sense of security and trust, as well as to give comfort and support the patients. The nurse's responsibility is to identify different needs of the patients for support and develop a relationship with them. Patients may express their pain, anxiety, fear and suffering by crying. No studies have been found which focus on how nurses can support patients who are crying in different ways and crying for different reasons.METHODS: A qualitative explorative study was performed. Semi-structured interviews were held with eight nurses aged 32-63 years (Median 40) working in Swedish palliative home care. The data were analysed using Qualitative Content analysis. Findings It was reported that the nurse should meet and confirm the patient during different types of crying episodes and should also be able to alternate between being close and physically touching the in such close contact with the patients, the nurse can provide emotional support by showing empathy, merely being present and letting the patients cry as much as they want. When the crying finally stops, the nurse can support the person by speaking with them, showing sensitivity, humility and respect for the patient's wishes. A few examples of the patients' need for information or practical support emerged. The nurse can emotionally support the person who is crying by just being present, confirming, showing empathy, offering a chance to talk and showing respect for their individual needs and the different ways they may cry.
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| 6. |
- Ryde, Ulf, et al.
(författare)
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Which functional groups of the molybdopterin ligand should be considered when modeling the active sites of the molybdenum and tungsten cofactors? A density functional theory study.
- 2009
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Ingår i: Journal of Biological Inorganic Chemistry. - : Springer Science and Business Media LLC. - 1432-1327 .- 0949-8257. ; 14:Online May 29, 2009, s. 1053-1064
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Tidskriftsartikel (refereegranskat)abstract
- A density functional theory study of the influence of the various functional groups of the molybdopterin ligand on electronic and geometric properties of active-site models for the molybdenum and tungsten cofactors has been undertaken. We used analogous molybdenum and tungsten complexes with increasingly accurate representation of the molybdopterin ligands and compared bond lengths, angles, charge distribution, composition of the binding orbitals, as well as the redox potentials in relation to each other. On the basis of our findings, we suggest using ligand systems including the pyrane and the pyrazine rings, besides the dithiolene function, to obtain sufficiently reliable computational, but also synthetic, models for the molybdenum and tungsten cofactors, whereas the second ring of the pterin might be neglected for efficiency reasons.
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| 7. |
- Van Severen, Marie-Céline, et al.
(författare)
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A quantum-mechanical study of the reaction mechanism of sulfite oxidase.
- 2014
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Ingår i: Journal of Biological Inorganic Chemistry. - : Springer Science and Business Media LLC. - 1432-1327 .- 0949-8257. ; 19:7, s. 1165-1179
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation of sulfite to sulfate by two different models of the active site of sulfite oxidase has been studied. Both protonated and deprotonated substrates were tested. Geometries were optimized with density functional theory (TPSS/def2-SV(P)) and energies were calculated either with hybrid functionals and large basis sets (B3LYP/def2-TZVPD) including corrections for dispersion, solvation, and entropy, or with coupled-cluster theory (LCCSD(T0)) extrapolated toward a complete basis set. Three suggested reaction mechanisms have been compared and the results show that the lowest barriers are obtained for a mechanism where the substrate attacks a Mo-bound oxo ligand, directly forming a Mo-bound sulfate complex, which then dissociates into the products. Such a mechanism is more favorable than mechanisms involving a Mo-sulfite complex with the substrate coordinating either by the S or O atom. The activation energy is dominated by the Coulomb repulsion between the Mo complex and the substrate, which both have a negative charge of -1 or -2.
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