Employing Equivalent Circuit Models to Study the Performance of Selenium-Based Solar Cells with Polymers as Hole Transport Layers.

Selenium(Se)-based solar cells (SSCs), known as one of the oldest solar cells, have regained intense attention due to the advantages of Se including direct bandgap, good stability, and single absorber. Among all kinds of device structures, conventional n-i-p SSCs with top organic hole transport layers (HTLs) show great potential since organic HTLs could be well-designed to smoothly extract holes from the Se single absorber and protect the Se surface. However, till now, the performance of Se solar cells with organic HTLs is not as good as expected. To address this issue, herein, the SSCs are first presented with organic polymers as the HTLs with the improved efficiency up to 4.3%, which is the highest one in organic HTLs-based SSCs. Additionally, comparing with perovskite solar cells, it is found that the recombination process is the key factor that influences the performance of SSCs. It is believed that the further optimization of the Se active layer and the design of new and suitable organic HTLs for SSCs should be the main focus to suppress the undesired recombination processes of Se films. Such realization would boost the efficiency of the as-fabricated SSCs.

Searching for the optimal precondition procedure for mesenchymal stem/stromal cell treatment: Facts and perspectives.

Mesenchymal stem/stromal cells are potential optimal cell sources for stem cell therapies, and pretreatment has proven to enhance cell vitality and function. In a recent publication, Li et al explored a new combination of pretreatment conditions. Here, we present an editorial to comment on their work and provide our view on mesenchymal stem/stromal cell precondition.

How surface-to-volume ratio affects degradation of magnesium: in vitro and in vivo studies.

Despite the many studies carried out over the past decade to determine the biodegradation performance of magnesium and its alloys, few studies focused on the effect of altered surface area to volume ratio on in vitro and in vivo degradation rate and osteogenesis. Here, high purity magnesium cylindrical rods with gradient of surface area to volume ratio were processed by excavating different numbers of grooves on the side surface. The immersion test in SBF solution and the rat femoral condylar bone defect model were used to evaluate the degradation of magnesium rods in vitro and in vivo, respectively. We demonstrated that, the increased number of grooves on the HP magnesium surface represented a decrease in the percentage of residual volume over time, not necessarily an increase in absolute degradation volume or a regular change in corrosion rate. Furthermore, there were strong linear correlations between the relative degradation volume and the initial surface-to-volume ratio of HP magnesium rods both in vitro and in vivo. The difference in the slope of this relationship in vitro and in vivo might help to determine the possible range of in vivo degradation rates via in vitro data. In addition, the corrosion rate is more suitable for evaluating bone formation surrounding the different HP magnesium rods. Our findings in this work may facilitate adjusting the in vivo degradation and osteogenesis of different kinds of orthopedic implants made of the same magnesium-based material, and thus, accelerate the clinical popularization and application.

Intervertebral Disc Progenitors: Lessons Learned from Single-Cell RNA Sequencing and the Role in Intervertebral Disc Regeneration.

The tremendous personal and economic burden worldwide caused by low back pain (LBP) has been surging in recent years. While intervertebral disc degeneration (IVDD) is the leading cause of LBP and vast efforts have been made to develop effective therapies, this problem is far from being resolved, as most treatments, such as painkillers and surgeries, mainly focus on relieving the symptoms rather than reversing the cause of IVDD. However, as stem/progenitor cells possess the potential to regenerate IVD, a deeper understanding of the early development and role of these cells could help to improve the effectiveness of stem/progenitor cell therapy in treating LBP. Single-cell RNA sequencing results provide fresh insights into the heterogeneity and development patterns of IVD progenitors; additionally, we compare mesenchymal stromal cells and IVD progenitors to provide a clearer view of the optimal cell source proposed for IVD regeneration.

Engineering electronic structure of graphene to boost Lithium-Storage performances.

Organic functionalization of graphene framework was an effective means used to boost the storage performances of lithium, but it lacked a universal strategic guideline for introducing functional groups (electron-withdrawing and electron-donating modules are overall classified). It mainly entailed designing and synthesizing graphene derivatives, in which the interference functional groups were necessarily excluded. To this end, a unique synthetic methodology based on graphite reduction cascaded by electrophilic reaction was developed. The electron-withdrawing-type groups (Br; trifluoroacetyl: TFAc) and electron-donating-type counterparts (butyl: Bu; 4-methoxyphenyl: 4-MeOPh) were readily attached to graphene sheets at a comparable functionalization degree. As the electron density of carbon skeleton was enriched by electron-donating modules, particularly for Bu units, the lithium-storage capacity, rate capability and cyclability were appreciably boosted. For example, they had 512 and 286 mA h g-1 at 0.5C and 2C, respectively; and 88 % of capacity retention after 500 cycles at 1C.

Transcriptome analysis of flower colour reveals the correlation between SNP and differential expression genes in Phalaenopsis.

BACKGROUND: Phalaenopsis is an important ornamental plant that has great economic value in the world flower market as one of the most popular flower resources. OBJECTIVE: To investigate the flower colour formation of Phalaenopsis at the transcription level, the genes involved in flower color formation were identified from RNA-seq in this study. METHODS: In this study, white and purple petals of Phalaenopsis were collected and analyzed to obtained (1) differential expression genes (DEGs) between white and purple flower color and (2) the association between single nucleotide polymorphisms (SNP) mutations and DEGs at the transcriptome level. RESULTS: The results indicated that a total of 1,175 DEGs were identified, and 718 and 457 of them were up- and down-regulated genes, respectively. Gene Ontology and pathway enrichment showed that the biosynthesis of the secondary metabolites pathway was key to color formation, and the expression of 12 crucial genes (C4H, CCoAOMT, F3'H, UA3'5'GT, PAL, 4CL, CCR, CAD, CALDH, bglx, SGTase, and E1.11.17) that are involved in the regulation of flower color in Phalaenopsis. CONCLUSION: This study reported the association between the SNP mutations and DEGs for color formation at RNA level, and provides a new insight to further investigate the gene expression and its relationship with genetic variants from RNA-seq data in other species.

[The posterior surgical treatment of old tuberculous kyphosis].

OBJECTIVE: To observe the results of posterior osteotomy and correction in the surgical treatment of old tuberculous kyphosis. METHODS: From June 2004 to December 2008, 31 cases of old tuberculous kyphosis with posterior osteotomy and correction technique were treated. There were 12 cases of male and 19 cases of female. The average age was 33.4 years. Pedicle subtraction osteotomy or vertebral column resection were applied in surgery. The kyphosis angle, lumbar lordosis angle and sagittal balance condition of the spine were measured before and after surgery, as well as follow-up. The Frankel grading system for neurological function of lower extremities, the Oswestry disability index (ODI) for life quality, and patient satisfactory index (PSI) for satisfaction of surgery were applied before surgery and at follow-up. RESULTS: The average kyphosis angle was 94° ± 27°, the average lumbar lordosis angle was 71° ± 20°, and the average sagittal C(7) plumb line was (-15 ± 44) mm away from the balance region before surgery. The average kyphosis angle decreased to 26° ± 11° in one week after surgery, with an improvement rate of 71.4%. The average follow-up time was 22.5 months. The average kyphosis angle was 28° ± 12° at the final follow-up, with an improvement rate of 70.0%. The average lumbar lordosis angle was 46° ± 11°, with an improvement rate of 35.1%. The postoperative kyphosis angle and lumbar lordosis angle were significantly different with that of pre-operation (for kyphosis angle: t = 16.3, P < 0.05; for lumbar lordosis angle: t = 8.1, P < 0.05). The average sagittal C(7) plumb line was (-4 ± 22) mm away from the balance region at the final follow-up, with an improvement rate of 73.4%. The Frankel grading were E in 13 cases, D in 13 cases, and C in 5 cases before surgery, and were E in 20 cases, D in 8 cases, and C in 3 cases at the final follow-up. The average ODI was 13 ± 12 before surgery, and was 7 ± 8 at the final follow-up, with an improvement rate of 45.2%. The PSI results showed a satisfied rate of 90.3%. CONCLUSION: Good results can be achieved by applying proper posterior osteotomy and correction technique according to the severity of old tuberculous kyphosis.

[Longterm outcome after the decompressive surgery for thoracic myelopathy due to the ossification of the ligamentum flavum].

OBJECTIVES: To investigate the long-term surgical outcome of thoracic myelopathy caused by the ossification of the ligamentum flavum (OLF) and evaluate the related risk factors. METHODS: Forty-four patients who underwent decompressive laminectomy with thoracic OLF between January 1990 and December 2005 and got more than 5 years follow-up were retrospectively reviewed. Among these 44 cases, there were 29 male and 15 female whose ages at operation were 52 years averagely (27-68 years). The 2-year follow-up results and long-term outcomes were classified according to the modified Epstein's standard, and then the rates of excellent or good (REG) were calculated. The correlation between the long-term REG and the patients' ages, durations of symptoms, decompressed levels, and dural leak were analyzed. RESULTS: The mean follow-up period of these 44 cases was 8.5 years (5-19 years). The REG at 2 years after laminectomy was 77.3% (34/44), while the long-term REG was 65.9% (29/44). There was one case who had suffered from an acute spinal cord injury got a poor post-operative outcome. The other 43 cases had chronic durations, including 22 cases whose pre-operative durations of symptoms were less than 12 months and 21 cases whose durations were equal to or more than 12 months. And the long-term REG of these two groups were 77.3% (17/22) and 57.1% (12/21) respectively (P>0.05). The REG of those cases whose decompression levels were limited in T1-T9 was 78.9% (15/19), while that of those cases whose laminectomy was relevant to thoracolumbar segment (T10-L2) was 58.3% (14/24) (P>0.05). There were 7 cases who had excellent or good short-term results and poor long-term outcomes. The reasons of these changes included coexistence of lumbar spinal stenosis in three cases and the growth of the OLF at the adjacent levels in four cases. CONCLUSIONS: Although the short-term results of the decompressive surgery for thoracic OLF is good, the regular long-term follow-up is necessary because the symptoms may reoccur or deteriorate secondary to lumbar spinal stenosis or the growth of OLF at the adjacent levels near former decompressive levels; the duration of symptoms which is more than one year and the decompression levels that is involved to T10-L2 segments are possibly related to the poor long-term outcomes.

Long-Term Follow-Up of Multilevel Thoracic Ossification of the Posterior Longitudinal Ligament Following Circumferential Decompression via Posterior Approach: A Retrospective Study.

OBJECTIVE: To examine the postoperative progression of multilevel thoracic posterior longitudinal ligament (OPLL) at circumferential decompression (CD) levels and evaluate the long-term results after CD via the posterior approach. METHODS: Clinical data from 16 patients with thoracic myelopathy secondary to OPLL who underwent CD at a single center were evaluated retrospectively from 2007 to 2014 and were followed up for more than 60 months. Patients of all sexes and ages were included in the study. Thin-slice computed tomography scans obtained at the time of surgery and the most recent follow-up were analyzed. The ossified area was measured on the axial reconstructed scan of the most obvious protrusion of ossification at the CD level. The neurological outcomes were evaluated using modified Japanese Orthopaedic Association (JOA) scores and Hirabayashi recovery rates (HRRs). Continuous variables were presented as the mean ± standard deviation and were analyzed using the Student's t-test, while categorical variables were tested using Fisher's exact test. RESULTS: Among all patients, the most predominant type was the mixed type (9/16, 56.3%), while the circumscribed type was only found in two patients (12.5%), and the continuous type was found in five patients (31.2%). Six cases were associated with ossification of the ligamentum flavum, and two cases were combined with cervical OPLL. The OPLL area at the CD level increased in all patients. The mean follow-up period was 5.5 ± 0.92 years (range 5-8 years). The mean area of ossification increased from 35.63 ± 39.23 mm2 at the time of surgery to 99.94 ± 65.39 mm2 at the last follow-up visit (P < 0.01). There was no internal fixation disorder on any computed tomography scan after the operation. The average JOA score of all patients improved from 4.2 ± 2.2 points before surgery to 8.4 ± 2.6 points at the final follow-up (P < 0.01). The overall HRR was 61.8%. None of the patients exhibited any neurological deterioration due to OPLL progression. One patient developed a severe gait disturbance due to worsening lumbar canal stenosis, an unrelated cause, but the other 15 experienced gait disturbance improvements. CONCLUSIONS: According to the long-term follow-up results, although OPLL progression did not decrease or stop after removing the OPLL mass, CD is a safe and effective procedure that can provide adequate reserve ventral space to cope with postoperative OPLL progression.

Ultrasimple air-annealed pure graphene oxide film for high-performance supercapacitors.

Realizing both high gravimetric and volumetric specific capacitances (noted as CW and CV, respectively) is an essential prerequisite for the next-generation, high performance supercapacitors. However, the need of electronic/ionic transport for electrochemical reactions causes a "trade-off" between compacted density and capacitance of electrode, thereby impairing gravimetric or volumetric specific capacitances. Herein, we report a high-performance, film-based supercapacitor via a thermal reduction of graphene oxide (GO) in air. The reduced, layer-structured graphene film ensures high electrode density and high electron conductivity, while the hierarchical channels generated from reduction-induced gas releasing process offer sufficient ion transport pathways. Note that the resultant graphene film is employed directly as electrodes without using any additives (binders and conductive agents). As expected, the as-prepared electrodes perform particularly well in both CW (420F g-1) and CV (360F cm-3) at a current density of 0.5 A g-1. Even at an ultrahigh current density of 50 A g-1, CW and CV maintain in 220F g-1 and 189F cm-3, respectively. Furthermore, the corresponding symmetric two-electrode supercapacitor achieves both high gravimetric energy density of 54 W h kg-1 and high gravimetric power density of 1080 W kg-1, corresponding to volumetric energy density of 46 W h L-1 and volumetric power density of 917 W L-1.

[The impact of thoracic and thoracolumbar angular kyphosis on pelvic shape and sagittal alignment].

OBJECTIVE: To analyze the impact of thoracic and thoracolumbar angular kyphosis on pelvic shape and sagittal alignment. METHODS: From May 2002 to June 2010, the sagittal spino-pelvic parameters were analyzed in lateral standing radiographs of 32 patients (mean age 29.6 years) with thoracolumbar angular kyphosis. The parameters included Cobb angle of kyphosis, lumbar lordosis (LL), pelvic incidence (PI), sacrum slope (SS), pelvic tilt (PT) and sagittal vertical axis (SVA). All pelvic parameters in the patients were compared with those reported in historical normal subjects. All patients were treated by using kyphotic correction and fusion. The preoperative and postoperative parameters were compared. The pelvic parameters were also compared between the patients with kyphotic apex located at T(1-8) and those located at T(9-12) and thoracolumbar junction. The linear regression analysis was used to investigate the independent factors of PI. RESULTS: The mean kyphosis was 90.1° (31° - 138°). The mean age of kyphosis occurrence was 6.1 years. The mean PI, SS and PT were 34.8°, 35.8° and -0.7° respectively. The PI and PT were significantly smaller (P < 0.001) in the patients than those in normal subjects while the SS was similar. The kyphosis was improved to 27.9° post-operatively. There was no difference in PI values between pre-operation and postoperation (P > 0.05). The PI and SS in patients whose kyphosis located at thoracic spine (T(1-8)) were significantly higher than those at T(9)-L(2). Instead of patients' age and LL, the preoperative Cobb angle of kyphosis and the levels where kyphosis located were two independent impact factors of PI. CONCLUSIONS: The kyphosis occurred at childhood may influence pelvic shape and alignment significantly. The lower kyphotic apex located and the bigger kyphosis, the greater impact on the pelvic morphology. The surgery can improve the kyphosis, but can not change the sagittal pelvic morphology. Early treatment of thoracolumbar angular kyphosis is beneficial not only to reconstruction of spine alignment but also to the formation of sagittal pelvic morphology.

High-Performance Flexible Asymmetric Supercapacitor Paired with Indanthrone@Graphene Heterojunctions and MXene Electrodes.

The energy density formula illuminated that widening the voltage window and maximizing capacitance are effective strategies to boost the energy density of supercapacitors. However, aqueous electrolyte-based devices generally afford a voltage window less than 1.2 V in view of water electrolysis, and chemically converted graphene yields mediocre capacitance. Herein, multi-electron redox-reversible, structurally stable indanthrone (IDT) π-backbones were rationally coupled with the reduced graphene oxide (rGO) framework to form IDT@rGO molecular heterojunctions. Such conductive agent- and binder-free film electrodes delivered a maximized capacitance of up to 345 F g-1 in a potential range of -0.2 to 1.0 V. The partner film electrode-Ti3C2Tx MXene which worked in the negative potential range of -0.1 to -0.6 V-afforded a capacitance as large as 769 F g-1. Thanks to the perfect complementary potentials of the IDT@rGO heterojunction positive electrode and Ti3C2Tx MXene negative partner, the polyvinyl alcohol/H2SO4 hydrogel electrolyte-based flexible asymmetric supercapacitor delivered an enlarged voltage window of 1.6 V and an impressive energy density of 17 W h kg-1 at a high power density of 8 kW kg-1, plus remarkable rate capability and cycling life (capacitance retention of ∼90% after 10000 cycles) as well as exceptional flexibility and bendability.

Transfunctionalization of graphite fluoride engineered polyaniline grafting to graphene for High-Performance flexible supercapacitors.

Low energy density is the major obstacle for the practical all-solid-state supercapacitors, which may be raised by the combination of the pseudocapacitance with the electrochemical double-layer capacitance. Although graphene and polyaniline have been demonstrated two effective materials, the synthetic route of graphene and their hybrid mode largely dictated the capacitive performances and cyclability of graphene/polyaniline nanocomposites. Herein, we employed commercial graphite fluoride as the precursor to obtain graphene with a well-preserved carbon lattice. After graphite fluoride functionalization by p-phenylenediamine (pPDA) and in situ oxidative polymerization of anilines, polyaniline (PANI) chains were covalently attached to graphene framework through pPDA bridges. Multiple characterizations were performed to confirm the covalent binding mode between graphene scaffolds and PANI partners, and electrochemical tests unraveled the as-prepared G-pPDA-PANI triads delivered a gravimetric capacitance as high as 638F g-1 and a further amplified volumetric capacitance (up to 759F cm-3). The bendable all-solid-state supercapacitors yielded an encouraging energy density of over 18 W   h L-1 at a power density high to 5,950 W L-1, while exhibiting an exceptional rate capability, cycling stability and mechanical flexibility.

Zwitterionic side chain-modified conjugated polymers with greatly enhanced ambipolar charge-transport mobilities.

A small amount of the 3-(hexyldimethylammonio)propane-1-sulfonate zwitterionic side chain was integrated into a diketopyrrolopyrrole ambipolar polymer to modulate its field-effect carrier-transport characteristics. It was found that such a modification can strengthen the interchain interaction, promote crystallization, and thus improve the hole and electron mobilities by 3.9- and 8.2-fold, respectively.

The clinical value of three-dimensional measurement in the diagnosis of thoracic myelopathy caused by ossification of the ligamentum flavum.

BACKGROUND: Thoracic ossification of the ligamentum flavum (OLF) is a major cause of thoracic myelopathy, which is often accompanied by multiple segmental stenosis or other degenerative spinal diseases. However, in the above situations, it is difficult to determine the exact segment responsible. The objective of this study was to analyze three-dimensional (3D) radiological parameters in order to establish a novel diagnostic method for discriminating the responsible segment in OLF-induced thoracic myelopathy, and to evaluate its superiority compared to the conventional diagnostic methods. METHODS: Eighty-one patients who underwent surgery for thoracic myelopathy caused by OLF from 2016 to 2020 were enrolled in this study as the myelopathy group, and 79 patients who had thoracic OLF but displayed no definite neurological signs from 2018 to 2020 were enrolled as the non-myelopathy group. We measured the one-dimensional (1D), two-dimensional (2D), and 3D radiological parameters, calculated their optimal cutoff values, and compared their diagnostic values. RESULTS: Significant differences were observed in the 1D, 2D, and 3D radiological parameters between the myelopathy and non-myelopathy groups (P<0.01). As a 3D radiological parameter, the OLF volume (OLFV) ratio (OLFV ratio = OLFV/normal canal volume × 100%) was the most accurate parameter for diagnosing OLF-induced thoracic myelopathy, with a diagnostic coincidence rate of 88.1%. We also found that an OLFV ratio of 26.3% could be used as the optimal cutoff value, with a sensitivity of 87.7% and a specificity of 88.6%. Moreover, the OLFV ratio [area under the curve (AUC): 0.92, 95% confidence interval (CI): 0.86-0.95] showed a statistically higher diagnostic value than the 1D and 2D parameters (AUC: 0.75, 95% CI: 0.67-0.81; AUC: 0.84, 95% CI: 0.77-0.89, respectively) (P<0.05). Pearson correlation analysis illustrated that the OLFV ratio was significantly negatively correlated with preoperative modified Japanese Orthopedic Association (mJOA) score (r=-0.73, 95% CI: -0.81 to -0.60, P<0.01). CONCLUSIONS: Our results demonstrate the superiority of the OLFV ratio over the conventional 1D and 2D computed tomography (CT)-based radiological parameters for the diagnosis of OLF-induced thoracic myelopathy. The novel diagnostic method based on the OLFV ratio will help to determine the responsible segment in multi-segmental thoracic OLF or when thoracic OLF coexists with other degenerative spinal diseases. The OLFV ratio also accurately reflects the clinical state of symptomatic patients with thoracic OLF.

[Clinical outcomes of surgical correction for ankylosing spondylitic kyphosis].

OBJECTIVE: To evaluate the clinical outcomes of posterior surgical corrective methods for ankylosing spondylitic kyphosis. METHODS: From June 2003 to June 2008, 21 cases of ankylosing spondylitic kyphosis received posterior surgical correction. There were 17 male and 4 female, and the average age was 39.5 years (range, 20 to 57 years). The total spine X-ray and CT were used to evaluate sagittal balance and thoracolumbar spine kyphosis angle, and chin brow-vertical angle was obtained from clinical lateral photograph. The surgical goal was to correct sagittal imbalance and chin brow-vertical angle. The simulated osteotomy was performed in computer before surgery to determine the correction methods. The surgical methods included: 16 cases of monosegmental closing osteotomy correction, 3 cases of anterior opening-posterior closing osteotomy correction, and 2 cases of combined pedicle subtraction osteotomy in thoracolumbar spine and Smith-Peterson osteotomy in lumbar spine. All patients were followed up after surgery, and the improvement of sagittal imbalance, chin brow-vertical angle and thoracolumbar spine kyphosis angle were assessed. The symptoms relief and satisfied rate were also evaluated. RESULTS: The average operation time was 4.4 hours, and the average blood loss was 1770 ml. Before surgery, the average thoracolumbar kyphosis angle was 62.1°, the average anterior shift of C(7) plumb line was 172.9 mm, and the average chin brow-vertical angle was 34.9°. The average follow-up was 28.8 months after surgery. The average correction rate of thoracolumbar kyphosis angle was 60%, the average improvement rate of anterior shift of C(7) plumb line was 64%, and the average correction rate of chin brow-vertical angle was 98%. The improvement rate of back pain was 64% during follow-up. The total surgical satisfactory rate was 95%. CONCLUSION: Based on the simulated osteotomy in computer before surgery, according to the characteristics of ankylosing spondylitic kyphosis, different posterior osteotomy and correction methods can achieve good results.

1,3,5-Triazine and dibenzo[b,d]thiophene sulfone based conjugated porous polymers for highly efficient photocatalytic hydrogen evolution.

Organic conjugated porous polymers, triazine-Ph-CPP and triazine-Th-CPP, are synthesized and characterized. Without further addition of co-catalysts, triazine-Ph-CPP exhibits a HER of 16 287 µmol g-1 h-1 and an apparent quantum yield of 61.5% at 365 nm, which demonstrates that the dibenzo[b,d]thiophene sulfone and 1,3,5-triazine based polymer is a unique prototype of a highly efficient hydrogen evolution photocatalyst.

Effect of decompression range on decompression limit of cervical laminoplasty.

BACKGROUNDS: Cervical posterior decompression surgery is used to relieve ventral compression indirectly by incorporating a backward shift of the spinal cord, and this indirect decompression is bound to be limited. This study aimed to determine the decompression limit of posterior surgery and the effect of the decompression range. METHODS: We retrospectively reviewed the data of 129 patients who underwent cervical open-door laminoplasty through 2008 to 2012 and were grouped as follows: C4-C7 (n = 11), C3-C6 (n = 61), C3-C7 (n = 32), and C2-C7 (n = 25). According to the relative location of spinal levels within a decompression range, the type of decompression at a given level was categorized as external decompression (ED; achieved at the levels located immediately external to the decompression range margin), internal decompression (ID; achieved at the levels located immediately internal to the decompression range margin), and central decompression (CD; achieved at the levels located in the center, far from the decompression range margin). The vertebral-cord distance (VCD) was used to evaluate the decompression limit. The C2-C7 angle and VCD on post-operative magnetic resonance images were analyzed and compared between groups. The relationship between VCD and decompression type was analyzed. Moreover, the relationship between the magnitude of the ventral compressive factor and the probability of post-operative residual compression at each level for different decompression ranges was studied. RESULTS: There was no significant kyphosis in cervical curvature (> -5°), and there was no significant difference among the groups (F = 2.091, P = 0.105). The VCD of a specific level depended on the decompression type of the level and followed this pattern: ED < ID < CD (P < 0.05). The decompression type of a level was sometimes affected by the decompression range. For a given magnitude of the ventral compressive factor, the probability of residual compression was lower for the group with the larger VCD at this level. CONCLUSIONS: Our study suggests that the decompression range affected the decompression limit by changing the decompression type of a particular level. For a given cervical spinal level, the decompression limit significantly varied with decompression type as follows: ED < ID < CD. CD provided maximal decompression limit for a given level. A reasonable range of decompression could be determined based on the relationship between the magnitude of the ventral compressive factor and the decompression limits achieved by different decompression ranges.

Dithieno[3,2-a:3',2'-j][5,6,11,12]chrysene diimides: a versatile electron-deficient building block for polymeric semiconductors.

In this work, dithieno[3,2-a:3',2'-j][5,6,11,12]chrysene diimides (DTCDI), an electron-deficient π-building block, were firstly incorporated into polymer main chains by using the 3,9-positions of chrysene and the α,α'-positions of thiophene units of DTCDI to connect with the 2,2'-bithiophene unit, affording copolymers P1 and P2, respectively. Due to their different connection ways the two polymers feature different optoelectronic properties.

Amphiphilic molecular design as a rational strategy for tailoring bicontinuous electron donor and acceptor arrays: photoconductive liquid crystalline oligothiophene--C60 dyads.

For tailoring solution-processable optoelectronic thin films, a rational strategy with amphiphilic molecular design is proposed. A donor-acceptor dyad consisting of an oligothiophene and C60, when modified with a hydrophilic wedge on one side and a paraffinic wedge on the other (1Amphi), forms over a wide temperature range a photoconducting smectic A liquid crystal having bicontinuous arrays of densely packed donor and acceptor units. In contrast, when modified with only paraffinic wedges (1Lipo), the dyad forms a smectic A liquid crystalline mesophase, which however is poorly conductive. As indicated by an absorption spectral feature along with a synchrotron radiation small-angle X-ray scattering profile, 1Lipo in the lamellar structure does not adopt a uniform head/tail orientation. Such defective donor and acceptor arrays likely contain a large number of trapping sites, leading to short-lived charge carriers, as observed by a flash photolysis time-resolved microwave conductivity study.