•Immobilization of Ni2+ ions at the inner surface of monodisperse spherical mesoporous SiO2 particles.•Monodisperse spherical mesoporous SiO2/Ni particles of 500±25nm diameter as metal affinity ...sorbents.•Diclofenac extraction by IMAC technique.•Addition of PFOS to IMAC eluents improves the recovery degree of diclofenac (up to 98%).•The obtained thermodynamics analysis data indicate the chemical nature of the DCF interaction with the surface of the sorbent.
In this research, a novel IMAC sorbent with high specificity for chlorine-containing compounds was developed. Ni-functionalized monodisperse spherical mesoporous silica particles of 500±25nm diameter were synthesized and their metal affinity properties were studied with the use of diclofenac as the model substance. The particles were aggregatively stable in the pH range of 3–12. The sorbent demonstrated a high adsorption capacity (0.60±0.06μg of DCF per 1mg of the sorbent) and high adsorption/desorption rate (20 and 5min was enough for the sorbent saturation and desorption of DCF, correspondingly). A mixture of eluents with addition of PFOS providing the almost complete recovery (98%) of diclofenac was first proposed. The monodispersity and the high sedimentation and aggregative stability of the particles provide the formation of a stable hydrosol even under ultrasound treatment which makes the mSiO2/Ni particles suitable for batch chromatography.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Effective conservation of exploited species requires an understanding of the motivations experienced by resource users. When use is illegal, it can be particularly difficult to distinguish users from ...non-users. The attitudes of local people are critical to conservation success, because they interact with social circumstances to determine behaviour. In this study we explore the factors influencing inferred poaching behaviour of the Critically Endangered saiga antelope (
Saiga tatarica) in six communities in three countries of the former Soviet Union. We show that local people have a good understanding of the species’ status and positive attitudes towards its conservation, regardless of their household’s inferred poaching status. Poaching is a low prestige occupation, and our analyses suggest that it is carried out by poor, unemployed households who have the means to hunt. These results are consistent for all villages. However we find important regional differences in hunting behaviour, linked to saiga population density and migration patterns, which have implications for the likely effectiveness of different conservation strategies. Community-based interventions are more likely to be appropriate in Russia, where saigas are present year-round and hunting is more subsistence based, than in the strongly seasonal Kazakhstan populations where economies of scale require organised poaching by fewer households. This case study illustrates the complex linkages between attitudes, social circumstances and behaviour in resource user behaviour, and highlights both the consistencies and differences in drivers of poaching between locations at a range of spatial scales.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Background:
Relapse of ALL remains the major cause of transplant failure. Relapse incidence after allo-HSCT is described in 30-40% of patients. Patients with ALL receive allo-HSCT with MAC more often ...because after RIC more relapses are expected.
The aim: To compare the frequency of relapse after allo-HSCT with RIC vs with MAC and to analyze the factors influencing the risk of relapse depending on the intensity of conditioning regimens.
Patients and methods:
Between 12/2000 and 09/2019 at RM Gorbacheva Research Institute a total of 235 children with ALL (median age of 10 years (0,5-18), underwent allo-HSCT. MAC (busulfan- or treosulfan-based) were used in 163 pts: 1st CR - 30 pts (MRD+ n=13), 2nd CR - 58 pts, 3rd or 4 CR - 27 pts, relapse - 48 pts. Allo-HSCT with RIC were performed in 72 pts: 1st CR - 12 pts (MRD+ n=9), 2nd CR - 29 pts, 3rd or 4 CR - 14 pts, relapse -17 pts. RIC consisted of fludarabine (30 mg/m2/d x 5 days) + melphalan (70 mg/m2/d x 2 days) or fludarabine (30 mg/m2/d x 5 days) + busulfan (4 mg/kg/d x 2 days). Matched related allo-HSCT was performed in 37 pts (16%), matched unrelated - in 128 pts (54%), haploidentical-in 70 pts (30%).
Cumulative incidence functions were used to estimate relapse incidence and NRM in a competing risk setting. Univariate analyses were performed using Grey test for cumulative incidences. Multivariate analyses were performed using the Cox proportional-hazard model.
Results:
Median follow-up was 5,4 and 4,5 years for МАС and RIC, respectively. Relapses were diagnosed in 105 pts (44%) during 1-39 months after allo-HSCT (median 7.5 months) (90% relapses were during first 18 mo), 74 pts after MAC; 31 pts after RIC (p=0,549). Relapses occurred significantly less frequent (p=0,007) in patients who had CR at the moment of allo-HSCT - 61 pts (35%) (RIC -32%; MAC -37%) compared patients who had a relapse or primary resistance 44 pts (68%) (RIC-74%; MAC - 65%). The risk of relapse after MAC is influenced by the presence of acute GVHD (p=0,007), the source of HSCs (PBSC vs BM, p=0,032), and the status of the disease (CR vs relapse) at the moment of allo-HSCT (p=0,001). The risk of relapse after RIC is influenced by the presence of acute GVHD (p=0,042), age at the moment of allo-HSCT 1-10 years (p=0,032), and the status of the disease (CR vs relapse) at the moment of allo-HSCT (p=0,001).
Multivariable analysis confirmed a significant impact of disease status at the moment of allo-HSCT whit MAC (p=0,001) and with RIC (p=0,002).
Presence of aGVHD was additional factor associated with lower relapse risk in multivariate analysis in pts after MAC (p=0,005).
Patients with active disease at the moment of HSCT had higher relapse-free survival after RIC (RIC-23% vs MAC- 12%, p=0,012). Salvage patients in whom the relapse was documented after HSCT had 28% and 38% probability of long-term OS after RIC and MAC, respectively (p=0,572).
Conclusion:
Relapse incidence after allo-HSCT with MAC and with RIC is comparable. The most significant factor affecting the risk of relapse is the status of the disease at the moment of allo-HSCT.
No relevant conflicts of interest to declare.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background: Traditionally, children with AML undergo аllo-HSCT with myeloablative conditioning (MAC). It is known that MAC is associated with significant transplant-related morbidity and mortality. ...Reduced-intensity conditioning (RIC) is used in patients not eligible for conventional conditioning therapy due to poor performance status and severe toxic complications after previous chemotherapy. RIC is a well-established treatment strategy in adult patients with comorbidities. But there is no conclusive evidence to support efficacy of RIC allo-HSCT in children suffering from different malignant diseases including AML.
The aim: To compare efficacy of different intensity conditioning regimens in children with high risk (HR) AML (according to AML-BFM protocols 1998 and 2004) and to identify factors which have a prognostic significance for overall survival (OS).
Patients and methods: Retrospective analysis was performed in 192 patients (pts) with AML (median age of 10 years (0.5-18 y.o.), who received allo-HSCT at R.M. Gorbacheva Research Institute between 08/2000 and 09/2019. MAC (busulfan- or treosulfan-based) were used in 109 pts: 1st CR - 46 pts (MRD+ n=11), 2nd CR - 18 pts, 3rd CR - 1 pt, relapse - 44 pts. Allo-HSCT with RIC were performed in 83 pts: 1st CR - 32 pts (MRD+ n=13), 2nd CR -19 pts, 3rd CR - 4 pts, relapse -28 pts (p=0,674). RIC consisted of fludarabine (30 mg/m2/d x 5 days) + melphalan (70 mg/m2/d x 2 days) or fludarabine (30 mg/m2/d x 5 days) + busulfan (4 mg/kg/d x 2 days). Indication for RIC allo-HSCT was poor performance status (Lansky/Karnofsky score ≤70%), or organ dysfunction due to previous therapy, or infectious complications at the moment of allo-HSCT. Allo-HSCT from matched related donor was performed in 30 pts (16%), from matched unrelated donor - in 98 pts (51%), haploidentical - in 64 pts (33%) and the donor distribution was not different between groups (p=0,878). Post-transplant Cy was included in GVHD prophylaxis regimens in 102 pts (53%). OS were estimated using Kaplan-Meier curves. Univariate analyses were performed using the log rank test for OS, Grey test for cumulative incidences. Multivariate analyses were performed using the Cox proportional-hazard model.
Results: Median follow-up was 5 years for МАС, 4.5 years for RIC. In both groups the median time to neutrophil engraftment >=0,5x109/l was D+16 (range D+8-52). Engraftment was observed in 67 pts (81%) after RIC and 94 pts (86%) after MAC (p=0,231). OS after RIC allo-HSCT in the 1st CR was 76% and after MAC - 68% (p=0,014), in 2nd CR 50% after RIC and 54% after MAC (p=0,058), in advanced disease 14% after RIC and 16% after MAC (p=0,394). The transplant-related mortality rate was 19% after RIC and 22% after MAC (p=0,546). Risk of relapse was 28% after RIC and 26% after MAC (p=0,456). Factors influencing OS after MAC were: 1) Remission status at the moment of allo-HSCT (р=0.001); 2) Presence of aGVHD grade I-II (р=0,005); 3) Relapse or MRD+ status after allo-HSCT (р=0.012); 4) Lansky score >70% (р=0,024). Factors influencing OS after RIC were: 1) Remission status at the moment of allo-HSCT (1st remission) (p=0,001); 2) Lansky score >70% (р=0,004).
Conclusion: The effectiveness of RIC and MAC is comparable in children with HR AML, but RIC demonstrated better results in 1st CR. The presence of I-II grade aGVHD had positive effect in MAC. Factors influencing OS in both groups were disease status at the moment of allo-HSCT and performance status before allo-HSCT
The use of RIC can be effective in patients, especially those who have undergone allo-HSCT in the 1st remission, while minimizing regimen-related toxicity in children who have undergone previous intensive treatment. Multicenter studies are warranted, especially for patients in the first CR, where long-term complications are of most importance.
No relevant conflicts of interest to declare.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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