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81.

Purpose

To describe the natural history and identify predictors of cancer-specific survival in patients who experience disease recurrence after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC).

Methods

Of 2,494 UTUC patients treated with RNU without neoadjuvant chemotherapy, 597 patients experienced disease recurrence. A total of 148 patients (25?%) received adjuvant chemotherapy before disease recurrence. Multivariable Cox regression model addressed time to cancer-specific mortality after disease recurrence.

Results

The median time from RNU to disease recurrence was 12?months (interquartile range 5?C22). A total of 491 (82?%) of 597 patients died from UTUC, and 8 patients (1.3?%) died from other causes. The median time from disease recurrence to death of UTUC was 10?months. Actuarial cancer-specific survival estimate at 12?months after disease recurrence was 35?%. On multivariable analysis that adjusted for the effects of standard clinicopathologic characteristics, higher tumor stages [hazard ratio (HR) pT3 vs. pT0?CT1: 1.66, p?=?0.001; HR pT4 vs. pT0?CT1: 1.90, p?=?0.002], absence of lymph node dissection (HR 1.28, p?=?0.041), ureteral tumor location (HR 1.44, p?<?0.0005) and a shorter interval from surgery to disease recurrence (p?<?0.0005) were significantly associated with cancer-specific mortality. The adjusted 6-, 12- and 24-month postrecurrence cancer-specific mortality was 73, 60 and 57?%, respectively.

Conclusions

Approximately 80?% of patients who experience disease recurrence after RNU die within 2?years after recurrence. Patients with non-organ-confined stage, absence of lymph node dissection, ureteral tumor location and/or shorter time to disease recurrence died of their tumor more quickly than their counterparts. These factors should be considered in patient counseling and risk stratification for salvage treatment decision making.  相似文献   
82.

Purpose

To show the radiological results of adolescent idiopathic scoliosis (AIS) patients treated with posterior fusion using all-pedicle-screw construct with correction carried out using a convex rod reduction technique.

Methods

Between October 2004 and June 2007, 42 AIS patients were treated with posterior fusion using all-pedicle-screw construct with correction done through the convex side. Two patients were lost to follow-up and were not included in the study. Forty patients had a minimum follow-up of 2 years. Patients were evaluated for the deformity correction in coronal and sagittal planes and for spinal balance.

Results

The mean preoperative Cobb angle of the major curve and secondary minor curves was 60° and 41°, respectively. Immediate postoperative mean Cobb angle of the major curve and secondary minor curves was 17° and 13°, respectively. Postoperative 2-year average major curve loss of correction was 7 %. Postoperative 2-year average minor curve loss of correction was 5 %. Preoperative thoracic kyphosis of 28° was changed to 22° in 2-years follow-up. The loss of thoracic kyphosis was most noted in hyperkyphotic patients.

Conclusions

The correction of AIS by convex-sided pedicular screws yields a coronal correction comparable to what is described in the literature for segmental concave-sided screws.  相似文献   
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Inflammatory cytokines are involved in autoimmune diabetes: among the most prominent is interleukin (IL)-1β. We postulated that blockade of IL-1β would modulate the effects of anti-CD3 monoclonal antibody (mAb) in treating diabetes in NOD mice. To test this, we treated hyperglycemic NOD mice with F(ab')(2) fragments of anti-CD3 mAb with or without IL-1 receptor antagonist (IL-1RA), or anti-IL-1β mAb. We studied the reversal of diabetes and effects of treatment on the immune system. Mice that received a combination of anti-CD3 mAb with IL-1RA showed a more rapid rate of remission of diabetes than mice treated with anti-CD3 mAb or IL-1RA alone. Combination-treated mice had increased IL-5, IL-4, and interferon (IFN)-γ levels in circulation. There were reduced pathogenic NOD-relevant V7 peptide-V7(+) T cells in the pancreatic lymph nodes. Their splenocytes secreted more IL-10, had increased arginase expression in macrophages and dendritic cells, and had delayed adoptive transfer of diabetes. After 1 month, there were increased concentrations of IgG1 isotype antibodies and reduced intrapancreatic expression of IFN-γ, IL-6, and IL-17 despite normal splenocyte cytokine secretion. These studies indicate that the combination of anti-CD3 mAb with IL-1RA is synergistic in reversal of diabetes through a combination of mechanisms. The combination causes persistent remission from islet inflammation.  相似文献   
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We report here that C–C coupling in tertiary amines for the synthesis of long chain and hindered amines might be efficiently performed over Pt and Pd catalysts. The mechanism study confirms similarity with the Guerbet reaction through dehydrogenation of the alkyl group and subsequent attack of the α-carbon atom by an alkyl group of another molecule. Finally, secondary amines and tertiary amines with longer alkyl chains are formed.

C–C coupling in tertiary amines for the synthesis of fatty and hindered amines proceeds efficiently over supported Pt and Pd catalysts.

Tertiary amines are important products in the modern chemical industry. Usually applications of tertiary amines include quaternary derivatives, amine oxides and betaines which are used in household, industrial, and institutional cleaners and disinfectants, wood treatment, personal care, oil field, and water treatment end-use markets.1Different methods have been reported for the synthesis of tertiary amines, for example, (1) reductive alkylation of aldehydes with secondary amines over metal catalysts,2 (2) N-alkylation of amines or nitroarenes with alkylhalides or alcohols,3 (3) hydroamination of olefins with amines4 and (4) amination of arylhalides.5 The main disadvantage of these routes is complex multistep processes and environmental pollution due to the usage of aggressive chemicals like halides. At the same time, these methods often provide low selectivities to desired tertiary amines.There are several classes of tertiary amines, which are especially important. The linear tertiary amines containing alkyl chain between 6 and 20 carbon atoms with two other short chain alkyl or piperidine ring are the commonly referred to fatty tertiary amines which are used for the synthesis of surfactants.6 Hindered tertiary amines containing iso-alkyl groups is another important class of tertiary amines which is hard to produce.7 These amines are used as a non-nucleophilic base and as a stabilizer for polymers.8The problem of increase of the chain length for alcohols and synthesis of isomerized alcohols have been solved by Marcel Guerbet in 1899.9 The Guerbet reaction involves coupling of two (or more) alcohol molecules through intermediate aldehyde formation, aldol condensation, dehydration of aldol product and hydrogenation of allylic aldehyde. The reaction proceed over bifunctional catalysts containing usually Cu, Ni metal for dehydrogenation/hydrogenation and base sites like MgO for C–H bond activation and coupling reaction.10Depending on the types of used alcohols in the reaction like long chain or short chain branched or unbranched products could be formed, respectively.11 This route would be an interesting opportunity for the synthesis of long chain or hindered amines. We have found that transformation of tertiary amines over Pd and Pt metallic catalyst proceed through C–C coupling with formation of heavier amines depending on the type of used tertiary amine.The transformation of non-symmetric tertiary amines over Pd black has been described in 1978 by Murahashi et al.12 The authors observed fast exchange of alkyls with formation of the mixture of tertiary amines. The reaction has been explained by insertion of palladium into a carbon–hydrogen bond adjacent to the nitrogen, leading to a highly active intermediate complex of an iminium ion. Afterwards a lot of reports have been devoted to C–C coupling of tertiary amines with different compounds like acrylates13 and alkynes14 usually activated by electro and photo-energy.15 The self-alkylation of triethylamine over noble metal catalysts in CO atmosphere has been described in the patent,16 however, no mechanism or further applications have been proposed. As far as we know, there are no scientific studies devoted to C–C coupling between tertiary amines. The reaction proceed by transfer of alkyl group from one molecule to another with formation of new C–C bond and increase of the chain length in one tertiary amine and formation of secondary amine from another molecule (Fig. 1).Open in a separate windowFig. 1Scheme of alkyl coupling of tertiary amines.Triethylamine (TEA) has been chosen as a model reagent for the reaction like ethanol in Guerbet reaction. Table 1 demonstrates catalytic performance of different noble metallic catalysts containing 5 wt% of the metal over carbon and alumina supports during transformation of TEA in batch reactor at 150–250 °C. The main reaction products might be subdivided into two groups: tertiary amines of condensation and secondary amines of dealkylation reactions. The main condensation products in the liquid phase involve butyldiethylamine, dibutylethylamine, hexyldiethylamine. The dealkylation products contain diethylamine, ethylamine and butylethylamine. The identification and assignment of the products by GC-MS and NMR is given in the Fig. S1–S5, ESI.Catalytic results of transformation of TEA over different catalysts (2 g TEA, p(N2) = 5 bar, 0.1 g catalyst, 0.24 mol% Pd, 5 h)
Catalyst T, °CTOF, h−1Conv.,%Selectivity to amines, mol%
CouplingDealkylation
123456
2001
Pd/C2006228920133261117
Pt/C20040062275344128
Pd/Al2O32001644741514292
Pd/Al2O3a20094273924211
Pd/Al2O3b20012837472483
Pd/Al2O3c2008324444491
Ru/Al2O32001434849
Ru/C200251338145522
Rh/Al2O32002
Pd/Al2O315013443532
Pd/Al2O3250881474302611
Pd black200684743
Ni/Al2O32006216514344
Open in a separate windowaH2 gas phase.bCyclohexane has been used as a solvent.cN2 pressure was 30 bar.The catalytic activity in transformation of TEA in inert atmosphere depends on the type of the metal, dispersion and support. The catalysts have been characterized by TEM and CO adsorption to determine the metal surface area (Table S1, Fig. S6–S7, ESI). TOF numbers over the same supports decrease in the row Pd > Pt > Ni > Ru ≈ Rh. It should be noted that activity is higher over carbon support in comparison with alumina. This catalytic behaviour correlates with activity of the metals in hydrogenation/dehydrogenation reactions. Indeed, Pt, Pd and Ni are well known as highly active hydrogenation catalysts in comparison with Rh and Ru which are good catalysts for hydrogenolysis reactions.17 This is why amination of aldehydes or alcohols over Pt and Pd lead to the synthesis of secondary and tertiary amines and Rh and Ru to selective synthesis of primary amines.18 It has to be noted that Pd black provides very low activity in transformation of TEA, which indicates on size, and electronic effect of Pd nanoparticles on intrinsic activity of TEA transformation. It explains mainly exchange activity of this catalyst in tertiary amines reported in the work of Murahashi.12Analysis of the dependence of the selectivity versus conversion over Pd/Al2O3 shows that selectivity to butyldiethylamine and diethylamine is close to 50% at low conversion and decreases with increase of the conversion (Fig. 2). The selectivity to the heavier products like dibutylethylamine and hexyldiethylamine is increasing with increase of the conversion. At the same time, we observe appearance of new dealkylation products like ethylamine, butylethylamine and dibutylamine. Thus, reaction takes consecutive character with transformation of initially formed butyldiethylamine further into the heavier products. The selective disproportionation to butyldiethylamine and diethylamine at reasonable conversion might be attained using organic solvent (Table 1). Indeed, inert solvent isolates the product from further reaction and improves the selectivity.Open in a separate windowFig. 2Selectivity to the products of TEA transformation depending on the conversion of TEA over Pd/Al2O3 (5 wt%) catalyst (T = 200 °C, 2 g TEA, p(N2) = 5 bar, 0.1 g catalyst, 0.24 mol% Pd, 1–17 h).This distribution of the products could be explained by combination of condensation and decomposition reactions of tertiary amines. However, analysis of the gas phase during transformation of TEA at the reaction conditions (200 °C) shows absence of hydrocarbons which means that reaction does not proceed through dealkylation of tertiary amines and most probably takes place by direct transfer of alkyl group from one tertiary amine to another one. Also carbon balance analysis shows that the molar amount of tertiary amines multiplied by amount of added C2 units corresponds to amount of amines with lost ethyl groups (Table S2, ESI).The key parameters for the reaction have been found to be reaction temperature and gas phase. At 150 °C there is almost no conversion of TEA (Table 1). Increase of the temperature to 200 and 250 °C resulted in increase of the conversion to 47 and 88%, respectively. Higher temperature resulted in significant increase of the contribution of heavy (dibutylethylamine, hexyldiethylamine) and light amines (ethylamine, ethylbutylamine). The dealkylation with formation of ethylene starts to take place only at high temperature (250 °C), which explains increase of the selectivity to ethylamine (Table 1).In the presence of hydrogen in the reactor activity was significantly lower which indicates that reaction is probably related to dehydrogenation activity of the catalyst (Table 1). Dehydrogenation activity of the catalyst might be easily controlled by pressure in the reactor. Increase of the pressure leads to suppression of the dehydrogenation activity but results in the higher selectivity to butyldiethylamine and diethylamine (Table 1).Guerbet reaction gives linear alcohols only during transformation of ethanol. Longer chain alcohols participate in condensation with formation of isomerized alcohols due to easier activation of C–H bond in CH2 groups.10 In order to verify that this rule works for tertiary amines we have performed reaction of transformation of tri-n-propylamine (TPA). The main product of the reaction over Pd/Al2O3 in comparison with TEA was tertiary amine with isomerized alkyl chain – 2-methyl-N,N-dipropylpentane-1-amine (Table 2) with only traces of linear hexyldipropylamine (Table S3, ESI). The identification and assignment of the products by GC-MS and NMR is given in the Fig. S8–S11, ESI. It indicates that propyl group attaches to the secondary β carbon atom of propyl group of another tertiary amine. In the case of TEA it leads to the synthesis of linear butyl chain.Catalytic results of transformation of TPA over Pd/Al2O3 (5 wt%) (2 g TPA, p(N2) = 5 bar, 0.1 g catalyst, 0.34 mol% Pd, 5 h)
Catalyst T, °CConv., %Selectivity to amines, mol%
78
Pd/Al2O320095444
Pd/Al2O3250696230
Open in a separate windowThe activity of TPA transformation was lower in comparison with TEA most probably due to steric restrictions in the condensation of alkyl groups. It has to be noted that stability of TPA toward decomposition at 250 °C was lower than for TEA which resulted in appearance of light hydrocarbons (propane, hexane) and increase of the contribution of dipropylamine and propylamine (Tables 2 and S3, ESI).One of the main disadvantages of this route of the synthesis of tertiary amines is that at high conversion reaction does not proceed in the direction of increase of only one alkyl chain. All groups of tertiary amine participate in the condensation. The possible solution of this problem could be in transformation of tertiary amines containing only one active group for coupling reaction. The alkyl groups might be not active in the coupling reaction, for example, when the role of two alkyls is playing aliphatic ring like in the case of N-ethylpiperidine (Table 3). The main products of the reaction are tertiary amines with selective growth of ethyl toward long chain alkyl group (Table S4, ESI). The identification and assignment of the products by GC-MS is given in the Fig. S12–S13, ESI.Catalytic results of transformation of N-ethylpiperidine over Pd/Al2O3 (5 wt%) (2 g N-ethylpiperidine, p(N2) = 5 bar, 0.1 g catalyst, 0.27 mol% Pd, 5 h)
Catalyst T, °CConv., %Selectivity to amines, mol%
9101112
Pd/Al2O320036542164
Open in a separate windowThe mechanism of the reaction of C–C coupling in tertiary amines has been studied by FTIR spectroscopy. Fig. 3 demonstrates results of adsorption of TEA over Pd/Al2O3 with subsequent heating. Adsorbed TEA demonstrates usual set of bands attributed to asymmetric and symmetric C–H stretching in CH2 and CH3 groups (2972, 2882 and 2940, 2827 cm−1), CH2 and CH3 bending (1460 and 1385 cm−1) and C–N stretching (1206 cm−1) vibrations. Gradual heating to 100 °C results in appearance of the band at 1580 cm−1 assigned to olefin double bond with significant decrease of the bands related to CH3 groups. Thus, the first step is dehydrogenation of TEA to enamines on the metal surface (Fig. 4). Enamine–imine tautomerization should lead to negative charge of terminal CH2 group and double C Created by potrace 1.16, written by Peter Selinger 2001-2019 N bond which explains disappearance of C–N stretching. The formation of palladium–iminium complex has been identified earlier.19,20Open in a separate windowFig. 3FTIR spectra during transformation of TEA over Pd/Al2O3.Open in a separate windowFig. 4Scheme of the mechanism of the reaction.Further heating of the sample to 200 °C leads to appearance of the new bands at 1643 and 1530 cm−1 which might be explained by formation of conjugated double bonds in smaller molecules. Enamines are well known as strong nucleophiles and have been used earlier in the reactions of alkylation, acylation etc.21 Similar to Guerbet condensation mechanism it should lead to attack of α-carbon attached to nitrogen by CH2 with formation of C–C bond (Fig. 4). The bond of N with tertiary carbon should not be stable and splits with removal of secondary amine like water in Guerbet condensation. In infrared cell at low pressure these amines will be in dehydrogenated state which leads to appearance of high frequency C Created by potrace 1.16, written by Peter Selinger 2001-2019 C group vibration. In the reactor subsequent hydrogenation of the formed product should result in the formation of butyldiethylamine and diethylamine as the main products of the reaction (Fig. 4).The formation of intermediate diamine compounds from TEA could be observed during analysis of the reaction kinetic by 13C and 1H NMR. The presence of weak signals of protons shifted down-field due to higher electronic density in –CH2– groups and signal of carbon shifted high-field due to presence of tertiary carbon indicates on the presence of diamine compounds in the reaction products (Fig. S3 and S4, ESI). The NMR analysis also shows presence of traces of olefins with 1H shift 7 and 3.6 ppm in the product of the reaction which indicates on hydrogen borrowing mechanism of the reactions (Fig. S5, ESI). GC-MS analysis also shows the presence of additional peak at high retention time, which according to MS spectrum, might be assigned to diamine compound (Fig. S1 and S2, ESI).The stability of intermediate diamine product should be higher in the case of delocalization of nitrogen electrons into the pi system of the benzene ring. In order to prove formation of intermediate diamine species, N,N-diethylaniline has been converted over Pd/Al2O3 catalyst (Table 4). N-Butyl-N-ethylaniline and N-ethylaniline are the main products of coupling and dealkylation at 53% conversion, respectively. Additionally 6% of diamine has been observed in the products by attack of α-carbon atom of ethyl group of one molecule by β-carbon atom of ethyl group of another molecule. The identification and assignment of the products by GC-MS is given in the Fig. S14–S15, ESI.Catalytic results of transformation of N,N-diethylaniline over Pd/Al2O3 (5 wt%) (2 g N,N-diethylaniline, p(N2) = 5 bar, 0.1 g catalyst, 0.36 mol% Pd, 5 h)
Catalyst T, °CConv., %Selectivity to amines, mol%
131415
Pd/Al2O32005364832
Open in a separate windowUsually Guerbet reaction requires besides metal also acid or base sites for condensation of aldehydes by activation of C–H bond.10,11 In the case of tertiary amines condensation proceed even over carbon support (Table 1) which means that it might take place directly over metal surface. The interaction of formed enamine species with metal surface through Pd–N bond could shift equilibrium to imine and promote coupling reaction. In order to check the state of metal during reaction of TEA we have added CO at room temperature after reaction of TEA at 200 °C. Fig. 5 demonstrates results of CO adsorption over parent Pd/Al2O3 catalyst. The peaks at 2090 cm−1 and 1977 cm−1 with shoulder at 1920 cm−1 are observed which might be assigned to linear and bridged bonded CO, respectively.22 The presence of TEA and products on the surface of metal leads to significant broadening of the CO peaks and shift to the lower frequencies. This result indicates on broad distribution of electronic states of Pd and higher electronic density on the metal leading to transfer from d-orbital of the metal to anti-bonding orbital of CO.23Open in a separate windowFig. 5FTIR CO adsorption with desorption in vacuum over Pd/Al2O3 before and after treatment of TEA.The imine form of adsorbed dehydrogenated TEA is highly polarized molecule and should interact strongly with Pd through double bond C Created by potrace 1.16, written by Peter Selinger 2001-2019 N and CH2 group (Fig. 5). The fact that the highest activity is observed over small size supported metal nanoparticles might be explained by strong stabilization of imine over defected Pd sites which provides high activity in the coupling reaction.To conclude, we uncovered that tertiary amines in the presence of Pd and Pt catalysts can transfer alkyl groups by C–C coupling with formation of tertiary amines with longer chains and secondary amines. The proposed mechanism based on FTIR results is similar to Guerbet condensation reaction and involves dehydrogenation with subsequent attack of α-carbon atom by carbanion with elimination of secondary amine. This method provides tool for the synthesis of long chain or hindered tertiary amines.  相似文献   
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