Photosensitization associated with light absorption and energy/electron‐transfer represents the central processes for photosynthesis. However, it's still a challenge to develop a heavy‐atom‐free ...(HAF) strategy to improve the sensitizing ability of polymeric photosensitizers. Herein, we propose a new protocol to significantly improve the photosensitization by decorating mother conjugated microporous polymer (CMP‐1) with polycyclic aromatic hydrocarbons (PAHs), resulting in a series of CMPs (CMP‐2–4). Systematic study reveals that covalent modification with PAHs can transfer charge to Bodipy in CMP to further facilitate both intersystem crossing and electron‐hole separation, which can dramatically boost energy‐/electron‐transfer reactions. Remarkably, CMP‐2 as a representative CMP can efficiently drive the photosynthesis of methyl phenyl sulfoxide with 92 % yield, substantially higher than that of CMP‐1 (32 %). Experiments and theory calculations demonstrate the structure‐property‐activity relationship of these CMPs, opening a new horizon for developing HAF heterogeneous photosensitizers with highly efficient sensitizing activity by rational structure regulation at a molecular level.
A proof‐of‐concept strategy to trigger charge transfer for improving photosensitization is the covalent modification of conjugated microporous polymers (CMPs) with polycyclic aromatic hydrocarbons (PAHs). Charge transfer from the PAH donor to the Bodipy acceptor in CMPs can facilitate both intersystem crossing and electron–hole separation, leading to excellent performance for both energy‐ and electron‐transfer reactions.
Abstract
The supraspinal mechanism plays a key role in developing and maintaining chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). However, it is not clear how white matter changes in ...young and middle‐aged males with CP/CPPS. In this cross‐sectional study, 23 CP/CPPS patients and 22 healthy controls (HCs) were recruited. Tract‐based spatial statistics was applied to investigate the differences in diffusion tensor imaging metrics, including fractional anisotropy (FA), mean diffusion (MD), radial diffusion (RD) and axial diffusion (AD), between CP/CPPS patients and HCs. The study also examined the association between white matter alterations and clinical variables in patients using correlation analysis. Compared with HCs, patients showed decreased FA, MD, RD and AD in the body and genu of the corpus callosum and right anterior corona radiata. In addition, they showed increased FA along with decreased MD, RD and AD in the left posterior limb of the internal capsule (PLIC‐L), left external capsule and left cerebral peduncle. The FA of PLIC‐L was negatively correlated with disease duration (
r
= −.54, corrected
p =
.017), while MD and RD were positively correlated (
r
= .45, corrected
p =
.042;
r
= .57, corrected
p =
.017). These results suggest that CP/CPPS is associated with extensive changes in white matter tracts, which are involved in pain processing. In particular, the FA, MD and RD values in the PLIC‐L were correlated with the disease duration, indicating that the long‐term course of CP/CPPS may have effects on the white matter microstructure of the pain perception pathways.
The construction of secondary building units (SBUs) in versatile metal–organic frameworks (MOFs) represents a promising method for developing multi‐functional materials, especially for improving ...their sensitizing ability. Herein, we developed a dual small molecules auxiliary strategy to construct a high‐nuclear transition‐metal‐based UiO‐architecture Co16‐MOF‐BDC with visible‐light‐absorbing capacity. Remarkably, the N3− molecule in hexadecameric cobalt azide SBU offers novel modification sites to precise bonding of strong visible‐light‐absorbing chromophores via click reaction. The resulting Bodipy@Co16‐MOF‐BDC exhibits extremely high performance for oxidative coupling benzylamine (~100 % yield) via both energy and electron transfer processes, which is much superior to that of Co16‐MOF‐BDC (31.5 %) and Carboxyl @Co16‐MOF‐BDC (37.5 %). Systematic investigations reveal that the advantages of Bodipy@Co16‐MOF‐BDC in dual light‐absorbing channels, robust bonding between Bodipy/Co16 clusters and efficient electron‐hole separation can greatly boost photosynthesis. This work provides an ideal molecular platform for synergy between photosensitizing MOFs and chromophores by constructing high‐nuclear transition‐metal‐based SBUs with surface‐modifiable small molecules.
A dual small molecules auxiliary strategy was proposed to construct the first high‐nuclear transition‐metal‐cluster‐based UiO‐architecture, where the N3− supplies a new modification site to precisely bond strong visible‐light‐absorbing chromophores via click reaction for cooperatively boosting photocatalysis.
Rational construction of earth-abundant heterogeneous photocatalysts is of great importance for efficient and sustainable solar energy utilization. Herein, we have developed a series of ...earth-abundant MOF photocatalysts (
Cu-1-MOF
-
Cu-5-MOF
) by incorporating Cu(
i
) complexes with different steric functional groups, which represents an efficient strategy for regulating the sensitizing ability of MOFs by restricting the excited state configuration of Cu(
i
) sensitizing centers. Remarkably,
Cu-5-MOF
with strong steric functional groups can efficiently drive photocatalytic oxidative coupling of benzylamine with a yield of 90.2%, 11 times higher than that with
Cu-1-MOF
without steric functional groups (8.2%). Systematic investigations revealed that the introduction of strong steric functional groups (
e.g. sec
-butyl) into Cu based MOFs can enhance their visible-light absorption, photochemical stability and electron-hole separation efficiency, which contributed to facilitating the utilization of solar energy and interface electron/energy transfer for efficient photosynthesis. This work provides a new insight into rationally constructing earth-abundant and efficient MOF photocatalysts by engineering copper(
i
) sensitizing centers with steric functional groups at the molecular level.
A series of earth-abundant and efficient MOF catalysts were constructed by incorporating Cu(
i
) complexes with different steric functional groups for boosting photosynthesis.
The aim of this study was to compare the metastatic patterns of synchronous bone metastasis (SBM) and metachronous bone metastasis (MBM) in nasopharyngeal carcinoma (NPC).
This study included bone ...metastases in NPC patients from 2005 to 2016 in a Chinese hospital. Cohort 1 was collected from 2005 to 2010 for discovery, and Cohort 2 from 2011 to 2016 for validation. The chi-squared test, Wilcoxon rank sum test, and Kaplan-Meier technique were used to compare site, time, and survival between cohorts 1 and 2. Prognostic factors were analyzed using univariate or multivariate Cox regression.
Cohort 1 had 112 individuals with SBM and 394 with MBM, and cohort 2 had 328 with SBM and 307 with MBM. The thoracic vertebra was the most frequently affected site of metastasis. Patients with SBM more often had metastasis to the cervical vertebrae compared with patients with MBM (34.5% vs. 22.3%, p < 0.05). Patients with SBM had better overall survival (42.2 months, 95% CI: 33.9-50.7) than patients with MBM (24.9 months, 95% CI: 22.2-28.7). Age at bone metastasis detection, metastasis to other organs, and more bone metastasis locations were associated with worse prognosis. The majority of MBMs occurred at 7 to 18 months after NPC diagnosis.
Radiotherapy does not modify the metastatic patterns of NPC bone metastases. Patients with SBM tend to have metastasis to the cervical vertebra, which is close to the nasopharynx. Paying more attention to bone metastases during follow-up in the first 2 years after an NPC diagnosis.
The thermal error of machine tool spindle system has become an important factor affecting machining accuracy. Measurement experiments of a 3-axis vertical milling machine spindle system were ...conducted to assess temperature fields and thermal errors. The fuzzy clustering and gray correlation algorithms were adopted to cluster the temperature measuring points and identify the temperature-sensitive points. Based on the adaptive chaos particle swarm optimization algorithm, thermal error models were established in the axial and radial directions for the spindle system, and the compensation effects were evaluated by the workpiece machining accuracy. The results showed that the number of temperature measuring points was reduced from 12 to 6. The residual range of measured and predicted thermal error values in the axial direction was 6.17–4.19 μm, and the modeling accuracy was 95.53%. The radial residual ranges were − 2.75–3.05 μm and − 2.10–2.15 μm, and the modeling accuracies were 90.74% and 91.10%, respectively. The model compensation effect was demonstrated remarkably in the verification experiments. The thermal error models showed high prediction precision, could improve machining accuracy and had strong engineering application value.
The aim of this study is to reduce the influence of machine tools spindle thermal error on machining accuracy in load machining state. The temperature and thermal error measuring system and ...experiments of the 3-axis vertical milling machine tool spindle in idling and load machining state were established and carried out. The differences in temperature and thermal error between the idling and load machining states were analyzed. Upon combining the fuzzy clustering and gray correlation algorithm, the temperature-sensitive points were optimized. The thermal error prediction models of machine tool spindle system in load machining state with the optimal specific cutting energy were established based on the adaptive chaotic particle swarm optimization algorithm, and the model prediction effects were evaluated. The results showed that the spindle system temperature and thermal error in load machining were higher than the idle state. Two temperature-sensitive points were selected that not only reduced the redundancy of temperature measuring points but also ensured the model prediction accuracy. The thermal error models prediction accuracy was above 90%, and the root mean square error and residual error were better than PSO and regression. The experimental results showed that the thermal error prediction models have a high prediction accuracy and engineering application value.
The construction of secondary building units (SBUs) in versatile metal-organic frameworks (MOFs) represents a promising method for developing multi-functional materials, especially for improving ...their sensitizing ability. Herein, we developed a dual small molecules auxiliary strategy to construct a high-nuclear transition-metal-based UiO-architecture Co
-MOF-BDC with visible-light-absorbing capacity. Remarkably, the N
molecule in hexadecameric cobalt azide SBU offers novel modification sites to precise bonding of strong visible-light-absorbing chromophores via click reaction. The resulting Bodipy@Co
-MOF-BDC exhibits extremely high performance for oxidative coupling benzylamine (~100 % yield) via both energy and electron transfer processes, which is much superior to that of Co
-MOF-BDC (31.5 %) and Carboxyl @Co
-MOF-BDC (37.5 %). Systematic investigations reveal that the advantages of Bodipy@Co
-MOF-BDC in dual light-absorbing channels, robust bonding between Bodipy/Co
clusters and efficient electron-hole separation can greatly boost photosynthesis. This work provides an ideal molecular platform for synergy between photosensitizing MOFs and chromophores by constructing high-nuclear transition-metal-based SBUs with surface-modifiable small molecules.
It is a great challenging task for selectivity control of both CO2 photoreduction and water splitting to produce syngas via precise microenvironment regulation. Herein, a series of UiO-type Eu-MOFs ...(Eu-bpdc, Eu-bpydc, Ru x -Eu-bpdc, and Ru x -Eu-bpydc) with different surrounding confined spaces were designed and synthesized. These photosensitizing Rux-Eu-MOFs were used as the molecular platform to encapsulate the CoII 4(dpy{OH}O)4(OAc)2(H2O)22+ (Co 4 ) cubane cluster for constructing Co4@Ru x -Eu-MOF (x = 0.1, 0.2, and 0.4) heterogeneous photocatalysts for efficient CO2 photoreduction and water splitting. The H2 and CO yields can reach 446.6 and 459.8 μmol·g–1, respectively, in 10 h with Co4@Ru 0.1 -Eu-bpdc as the catalyst, and their total yield can be dramatically improved to 2500 μmol·g–1 with the ratio of CO/H2 ranging from 1:1 to 1:2 via changing the photosensitizer content in the confined space. By increasing the N content around the cubane, the photocatalytic performance drops sharply in Co4@Ru 0.1 -Eu-bpydc, but with an enhanced proportion of CO in the final products. In the homogeneous system, the Co 4 cubane was surrounding with Ru photosensitizers via week interactions, which can drive water splitting into H2 with >99% selectivity. Comprehensive structure–function analysis highlights the important role of microenvironment regulation in the selectivity control via constructing homogeneous and heterogeneous photocatalytic systems. This work provides a new insight for engineering a catalytic microenvironment of the cubane cluster for selectivity control of CO2 photoreduction and water splitting.
This research is based on the modeling, internal structure analysis, and automation of a cassava grinding machine. For the design, the single-cylinder grinder was chosen due to its advantages, ...notably simplicity and versatility. The grinding method used in this type of grinder is compression. The mechanical design and simulation software first allowed for the design of the grinder and then for performing static analyses under three loads (P1 = 10000N, P2 = 15000N, and P3 = 20000N). The results of these tests led to the selection of P3 = 20000N as the straightening load, with a maximum stress value in the static analysis of 88,18 MPa and a maximum deformation of 0,000358 under the force of load P3. Additionally, the frequency analysis distinguished five resonance modes. The results for each mode concluded that no resonance would affect the machine, thus ensuring stable operation. Furthermore, fatigue, frequency, and safety factor studies showed that the machine could withstand a load of m3 = 2000 kg without damage, with a service life of 1e+09 cycles. Considering the total number of life cycles, which is 1e+09 cycles, this means that the machine will have a service life of 347000 years, with a total grinding output of 2e+12 kg of cassava and 5840000 kg per year. The factor of safety is FoS = 1,78, indicating a sufficient margin for safe operating conditions. The automation of the grinder was carried out using a GRAFCET model and a sophisticated human-machine interface (HMI), providing an additional safety point for the machine and allowing the operator to monitor the operation via a simple graphical interface. This automation enables continuous operation with minimal human intervention, thereby improving the efficiency and safety of the cassava grinding process.
