Sunshine is an Important Determinant of Vitamin D Status Even Among High‐dose Supplement Users: Secondary Analysis of a Randomized Controlled Trial in Crohn's Disease Patients

Sunshine is considered to be the most important source of vitamin D. Due to an increased risk of skin cancer, sun avoidance is advised, but this directly contributes to the high prevalence of vitamin D deficiency. The simple solution is to advise vitamin D supplementation. The aim of this study was to examine the absolute and relative contribution of sunshine and supplementation to vitamin status. This study was a secondary analysis of an RCT of 92 Crohn's disease patients in remission (49% female, median age = 44). Participants were randomized to 2000 IU day^?1 of vitamin D3 or placebo for 1 year, with 25‐hydroxyvitamin D (25(OH)D) being measured at baseline and every 4 months. Based on participant's place of residence, daily ambient UVB dose at wavelengths that can induce vitamin D synthesis (D‐UVB) was obtained. Cumulative and weighted ambient D‐UVB (cw‐D‐UVB) exposure prior to each blood draw was calculated for each participant. Linear regression analysis and multilevel modeling were used to examine the association between UVB exposure, supplementation and 25(OH)D concentration. There was considerable annual variation in D‐UVB, cw‐D‐UVB and 25(OH)D. Both supplementation and cw‐D‐UVB were found to be strongly associated with 25(OH)D: in multilevel model, an increase of approximately 6 nmol L^?1 for every 100 kJ m^?2 in cw‐D‐UVB was found, among those receiving placebo and supplementation (P < 0.0001). Treatment was associated with increase of 23 nmol L^?1 (P < 0.0001). Sunshine is an important determinant of 25(OH)D concentration, even in those who are taking high‐dose vitamin D supplements and reside at a higher mid‐latitude location.     

Precise analysis of thyroxine enantiomers in pharmaceutical formulation by mobility difference based on cyclodextrin

Identification and determination of chiral pharmaceutical residues is still a challenging analytical puzzle. In this work, a simple, rapid, and effective method for chiral D/L-tetraiodothyronine (T4) separation and quantitative was developed based on host–guest recognition using ion mobility spectrometry-mass spectrometry (IMS-MS). The D/L-T4 enantiomers were mobility separated by their diastereomeric complexes through mixing with cyclodextrin (CD) and metal ions. D/L-T4 was first separated by complexing with host molecule (α-, β-, γ-CD), observing weak peak-to-peak resolution (R_p-p) by the formed binary complex [CD + D/L-T4-H]⁺, and the R_p-p decreased with the CD size increasing. However, the separation effect of D/L-T4 was much improved with the addition of divalent metal ions (G²⁺) by the formed ternary complex [CD + D/L-T4 + G]²⁺. In comparison, α-CD related complexes can possess the best separation effect for D/L-T4 in most cases. Considering the high selectivity, non-toxic, and chemically stable of β-CD, [β-CD + D/L-T4 + Ca]²⁺ was selected for D/L-T4 analysis (R_P-P = 0.764). Whereafter, chemical theoretical conformations for [β-CD + D/L-T4 + H]⁺ and [β-CD + D/L-T4 + Ca]²⁺ were optimized, discovering similar micro-interaction modes between [β-CD + D-T4 + H]⁺ and [β-CD + L-T4 + H]⁺; while with the addition of Ca²⁺, significantly different interaction modes were observed between [β-CD + D-T4 + Ca]²⁺ and [β-CD + L-T4 + Ca]²⁺. And theoretical collision cross section (CCS) trends for the complexes were consistent with that of the experimental results. Additionally, calibration curves were linear within 1.00 to 10⁴ ng mL^?1 with coefficient (R² > 0.99), gaining the limit of detection (LODs) calculation of 0.11 ng mL^?1, and the detection range between D-T4 and L-T4 of 45.6:1 to 1:59.8. Finally, the method was applied for D/L-T4 detection in Levothyroxine tablets, the detection content has good consistency on drug labeling. Because the proposed method exhibited good analytical performance in terms of speed, selectivity, sensitivity, and reproducibility of the measurements, that can be a promising strategy for effective D/L-T4 detection in pharmaceutical industries or other practical samples.     

Construction of three-dimensional/one-dimensional heterostructure of flower-like Sr nanoflowers on Se microrods decorated on reduced graphene oxide: an efficient electrocatalyst for oxidation of promethazine hydrochloride

Three-dimensional (3D) strontium flowers were grown on well-defined one-dimensional (1D) selenium microrods using a simple hydrothermal technique at 180 °C. This resulted in the formation of a unique 3D/1D material which was ultrasonically treated with reduced graphene oxide to form a hybrid composite. The structural and functional analysis were performed using X-ray diffraction spectroscopy which rendered the material as pure and crystalline and Fourier transform infrared spectroscopy, respectively. X-ray photoelectron spectroscopy was performed to unravel the elemental composition and successful formation of the composite. Field emission scanning electron microscopy and transmission electron microscopy were performed to study the unique morphological features of the material. It was further used to fabricate a sensor for the detection of promethazine hydrochloride (PMZH) drug. The sensor showed a very low detection limit of 7.7 nM at a linear working range of 0.99 μM–900 μM and a sensitivity of 5.282 μA μM^?1 cm^?2. The sensor showed an excellent analyte recovery rate for real-time analysis in biological and environmental samples. The results suggested that the sensor is effective for the detection of PMZH with feasibility for future commercialization.     

Slippage mutation rates in 15 autosomal short tandem repeat loci for forensic purposes in a Southeastern Brazilian population

Well‐defined estimates of mutation rates in highly polymorphic tetranucleotide STR loci are a prerequisite for human identification in genetics laboratory routines useful for civil and criminal investigations. Studying 15 autosomal STR loci of forensic interest (CSF1PO, D2S1338, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D19S433, D21S11, FGA, TH01, TPOX, and vWA), we detected 193 slippage mutations (189 one‐step and four two‐step mutations) in 148 875 parent‐child allelic transfers from 5171 paternity cases with true biological relationship (15 096 individuals; 4754 trios and 417 duos; 9925 meiosis) from the state of São Paulo, a very representative population of Brazil. The overall mutation rate was 1.3 × 10^?3 and the highest rates were observed at loci vWA (2.8 × 10^?3), FGA and D18S51 (2.7 × 10^?3 for both), while loci TH01 and TPOX did not present any mutations. The mean slippage mutation rate of paternal origin (1.8 × 10^?3) was six times higher than that observed for maternal origin (0.3 × 10^?3).     

Two-dimensional nanosheets of metal–organic frameworks with tailorable morphologies

The controlled preparation of two-dimensional (2D) nanosheets of metal–organic frameworks (MOFs), with tailorable methodologies, properties, and applications, is of significant importance. Here, in this work, by subtle control of the ultrasonic duration and solvent polarity, the iron(II)-based 2D MOF Fe(pyz)₂Cl₂ (pyz = pyrazine) has been elegantly tailored into 2D nanosheets (lateral size ≥500 nm in aqueous, with ultrasonic duration of 30 min) and one-dimensional (1D) nanoribbons (lateral size ≤100 nm in ethanol solution, with ultrasonic duration of 90 min). The aqueous suspension of 2D nanosheets was featured with thermal-induced spin-state transition at around room temperature and can be used as effective Fenton catalysts for degradation of water-soluble organic dyes, whereas the ethanol suspension of 1D nanoribbons can act as a versatile nanoplatform for trans-to-cis isomerization of 4, 4′-azopyridine. These results may provide a novel strategy for the controlled preparation of layered nanomaterials.     

Two-dimensional copper oxide/zinc oxide nanoflakes with three-dimensional flower-like heterostructure enhanced with electrocatalytic activity toward nimesulide detection

The strategy of building two-dimensional (2D) metal oxide nanoflakes has inspired several innovations in different fields of application on account of its tremendous significance. It includes ultrathin planar surface, large charge carrier mobility, and tunable band structures, providing unprecedented features for sensing. Moreover, the intercalation of 2D dimensions to 3D superstructures will result in improved and dual advantages of both 2D/3D. The construction of 2D/3D copper oxide zinc oxide nanocomposite as electrode material for specific detection of nimesulide (NMS) is herein reported. The conversion of 2D CZ nanoflakes to 3D CZ microflowers was possibly achieved via the self-assembly process. This simple and cost-effective development of the CZ composite was characterized for evaluating the physical, chemical, and morphological properties. The highly crystalline nature of CZ was observed from powder X-ray diffraction and X-ray photoelectron spectroscopy analysis. The formation of 2D nanoflakes of CZ was strongly confirmed from field emission scanning electron microscopy and high-resolution transmission electron microscopy images. To verify the strong attachments, Fourier transforms infrared spectroscopy spectra were analyzed. Electrochemical sensing of NMS at CZ fabricated glassy carbon electrode reflects higher electrocatalytic activity with a linear range of NMS addition from 0.299 μM to 319.15 μM. The lower detection limit was about 0.005 μM with a sensitivity of 7.152 μAμM^?1 cm². The CZ nanocomposite will be more applicable for sensing several drugs with enriched active sites, higher conductivity, and large surface area raised from low-cost metal oxides when compared with highly conducting materials.     

Pseudonocardides A – G,New γ‐Butyrolactones from Marine‐derived Pseudonocardia sp. YIM M13669

Seven new γ‐butyrolactones, named pseudonocardides A – G ( 1  –  7 ), were isolated from the marine‐derived actinomycete strain Pseudonocardia sp. YIM M13669. Their structures were elucidated on the basis of spectroscopic data including 1D‐ and 2D‐NMR, and HR‐ESI‐MS. The absolute configuration of 1 was determined by X‐ray crystallographic analysis of 1a (4‐bromobenzoate derivative of 1 ). The antibacterial activity against Mycobacterium smegmatis MC²155 and cytotoxicities of compounds 1  –  7 were evaluated in this study.     

Identification of flavonoids in Dendrobium huoshanense and comparison with those in allied species of Dendrobium by TLC,HPLC and HPLC coupled with electrospray ionization multi‐stage tandem MS analyses

Dendrobium huoshanense, a unique species in the genus Orchidaceae, is only found in China and is known as “mihu”. Due to the lack of quality control, the use of D. huoshanense in the herbal market has been limited. In this study, methods based on thin‐layer chromatography, high‐performance liquid chromatography and high‐performance liquid chromatography coupled with electrospray ionization multi‐stage tandem mass spectrometry were used to identify the flavonoids in D. huoshanense and distinguish this species from other Dendrobium species. Using thin‐layer chromatography, a characteristic band was observed for D. huoshanense, and this band was absent from the thin‐layer chromatography plates of other Dendrobium species. Then, using high‐performance liquid chromatography, nine peaks of flavonoids were observed in the chromatograms of ten batches of D. huoshanense. Ultimately, 22 flavonoids in D. huoshanense were identified by multi‐stage tandem mass spectrometry, and 11 of these compounds are being reported from D. huoshanense for the first time. In addition, two compounds both with molecular weights of 710, were identified as being unique to D. huoshanense; one of these compounds, apigenin‐6‐C‐α‐L‐rhamnosyl‐(1→2)‐β‐D‐glucoside‐8‐C‐α‐L‐arabinoside, was proven to be responsible for the characteristic thin‐layer chromatography band of D. huoshanense. These analysis methods can be applied for the identification and quality control of D. Huoshanense.     

Direct quantification of deoxynivalenol glucuronide in human urine as biomarker of exposure to the <Emphasis Type="Italic">Fusarium</Emphasis> mycotoxin deoxynivalenol

The direct quantification of deoxynivalenol glucuronide (DON-GlcA) by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and its application as a biomarker of exposure to the Fusarium mycotoxin deoxynivalenol (DON) is reported. Usually, DON exposure is estimated from dietary average intakes or by measurement of the native toxin in urine after enzymatic hydrolysis with β-glucuronidase. These methods are time-consuming, expensive, and fail to determine the ratio of DON to DON-GlcA in a simple one-step procedure. One of the main reasons for the use of indirect methods is the unavailability of DON-GlcA standards. Consequently, DON-3-O-glucuronide (D3GlcA) was synthesized and used to develop a method allowing quantification of both DON and D3GlcA by a simple “dilute and shoot” approach without the need for any cleanup. Limit of detection and apparent recovery of D3GlcA was 3 μg l⁻¹ and 88%, respectively. The identity of D3GlcA in human urine was confirmed by comparison with LC-MS/MS measurements of the synthetically produced D3GlcA standard which was also used for external calibration. The applicability of the method was demonstrated through the analysis of urine samples obtained from a volunteer during regular and cereal-restricted diet, respectively. In regular-diet urine samples, D3GlcA was quantified in concentrations >30 μg l⁻¹ by this approach.     

Effect of inorganic oxide supports on the activity of chromium‐based catalysts in ethylene trimerization

Novel heterogeneous catalysts were prepared using immobilization of bis(2‐decylsulfanylethyl)amine–CrCl₃ (Cr‐SNS‐D) on various supports, namely commercial TiO₂, Al₂O₃ and magnetic Fe₃O₄@SiO₂ nanoparticles, to yield solid catalysts denoted as support@Cr‐SNS‐D. The structure of the catalysts was confirmed on the basis of spectroscopic analyses, N₂ adsorption–desorption and inductively coupled plasma (ICP) analysis. The surface areas of Al₂O₃@Cr‐SNS‐D, Fe₃O₄@SiO₂@Cr‐SNS‐D and TiO₂@Cr‐SNS‐D catalysts were determined to be 70, 23 and 41 m² g^?1, respectively. A decrease in surface area from that of the supports clearly establishes accurate immobilization of Cr‐SNS‐D catalyst on the surface of the parent carriers. The loading of Cr was determined to be 0.02, 0.16 and 0.11 mmol g^?1 for Cr‐SNS‐D supported on TiO₂, Al₂O₃ and Fe₃O₄@SiO₂, respectively, using ICP analysis. After preparation and full characterization of the catalysts, ethylene trimerization reaction was accomplished in 40 ml of dry toluene, at 80°C and 25 bar ethylene pressure and in the presence of methylaluminoxane (Al/Cr = 700) within 30 min. The supported chromium catalysts were found to be efficient and selective for the ethylene trimerization reaction. The highest activity (74 650 g_1‐hexene g_Cr^?1 h^?1), as well as no polyethylene formation during reaction processes, was observed when TiO₂ was used as the catalyst support.     

Effect of Ceramide on Mesenchymal Stem Cell Differentiation Toward Adipocytes

Proinflammatory cytokines such as tumor necrosis factor (TNF) α are well known to inhibit adipocyte differentiation. TNF-α triggers ceramide synthesis through binding of TNF-α to its p55 receptor. Therefore, ceramide is implicated in many of the multiple signaling pathways initiated by TNF-α. In breast tissue engineering, it is important to know how to modulate adipocyte differentiation of the stem cells with exogenous additives like ceramide in vitro. We hypothesized that stem cell adipogenesis could be retained in TNF-α-treated preadipocytes in which ceramide synthesis was blocked and that exogenous ceramide could inhibit adipocyte differentiation. We first studied the effect of ceramide synthase inhibitor, Fumonisin B2, on the adipogenesis of murine mesenchymal stem cells (D1 cells), treated with TNF-α. We then studied the effect of specific exogenous C6-ceramide on D1 cell viability and differentiation. It was found that 1 ng/ml of TNF-α significantly inhibited D1 cell adipogenesis. Cells treated with 5 μM of Fumonisin B2 were able to undergo adipogenesis, even when treated with TNF-α. High concentrations of exogenous C6-ceramide (>50 μM) had an inhibitory effect, not only on the pre-confluent proliferation of the D1 cells but also on the post-confluent cell viability. High concentrations of C6-ceramide (>50 μM) also inhibited mitotic clonal expansion when D1 cell differentiation was induced by the addition of an adipogenic hormonal cocktail. C6-ceramide at low concentrations (10–25 μM) inhibited lipid production in D1 cells, demonstrated by decreased levels of both total triglyceride content and specific fatty acid composition percentages. Genetic expression of peroxisome proliferator-activated receptor (PPAR) γ and aP2 in D1 cells was reduced by C6-ceramide treatment. CCAAT/enhancer-binding protein (C/EBP) β levels in D1 cells were reduced by C6-ceramide treatment during early differentiation; PPARγ and aP2 protein levels were reduced at terminal differentiation. C6-ceramide at lower concentrations also decreased lipid accumulation of differentiating D1 cells. Our results suggest that ceramide synthase inhibitor retains the adipogenic potential of TNF-α-treated mesenchymal stem cells, while exogenous ceramide at lower concentrations inhibit the adipogenesis of mesenchymal stem cells. Ceramide, therefore, could be a modulator candidate in breast tissue engineering strategies.     

Cytotoxic phenolic glycosides from <Emphasis Type="Italic">Boschniakia himalaica</Emphasis>

A new lignan glycoside, 9-acetyl lanicepside B (1), was isolated from the whole plant of Boschniakia himalaica, along with five known compounds, lanicepside A (2), plantainoside D (3), plantamajoside (4), (–)-woonenoside XI (5), and syringin (6). The new compound's structure was established on the basis of detailed 1D and 2D NMR spectroscopic analysis and chemical evidence. 9-Acetyl lanicepside B (1) showed weak in vitro cytotoxic activities against A549 and P388 with IC₅₀ values of 64.7 μM and 72.5 μM, respectively. Syringin (6) showed moderate in vitro cytotoxic activities against A549 and HL-60 with IC₅₀ values of 32.5 μM and 41.8 μM, respectively.     

1D and 2D solid-state metallosupramolecular arrays of freebase 5,10,15,20-tetra(4-pyridyl)porphyrin, peripherally linked by zinc and manganese ions

Freebase 5,10,15,20-tetra(4-pyridyl)porphyrin (TPyP) is able to assemble into crystalline rigid 1D and 2D metallosupramolecular arrrays via exocyclic coordination with tetracoordinate and hexacoordinate metal ions, respectively. In this contribution we report on two coordination polymers of μ ⁴-bridging freebase TPyP with zinc and manganese halide moieties. The structure of [(ZnBr₂)₂TPyP] · 6 TCE (2) (TCE = 1,1,2,2-tetrachloroethane) consists of 1D polymeric chains. The topology of [(MnCl₂)TPyP] · 6 TCE (3) is the (4,4) square grid type. The crystal structure of the known compound [(HgI₂)₂TPyP] · 4 TCE (1) was redetermined by X-ray crystallography.     

One dimensional macropore-array formation on low doped n-type silicon

Macropores with diameters between 0.1 μm and 0.8 μm show technological significance but become difficult to obtain on low doped n-type silicons. In this study, via anodizing samples with prestructured linear defects, one dimensional (1D) densely arrayed macropores with depths up to 15 μm and diameters between 100 nm and 1 μm were produced with fast speed on low doped n-Si. The pore density increases with reduced current densities: this phenomenon was found to be largely dominated by physics rather than by chemistry. Not least, SCR effects alone were excluded as additional stabilizers of the 1D macropore arrays; the interaction between diffusion and tunneling effects was proved to play a major role instead. Simultaneously, the gradual transition from macropore to mesopore formation, not well understood to date, was experimentally displayed and theoretically interpreted.     

Tetra‐ammonium Zinc Phthalocyanine to Construct a Graded 2D–3D Perovskite Interface for Efficient and Stable Solar Cells

The crystallographic defects inevitably incur during the solution processed organic‐inorganic hybrid perovskite film, especially at surface and the grain boundaries (GBs) of perovskite film, which can further result in the reduced cell performance and stability of perovskite solar cells (PSCs). Here, a simple defect passivation method was employed by treating perovskite precursor film with a hydrophobic tetra‐ammonium zinc phthalocyanine (ZnPc). The results demonstrated that a 2D‐3D graded perovskite interface with a capping layer of 2D (ZnPc)_0.5MA_n ? 1Pb_nI_3n + 1 perovskite together with 3D MAPbI₃ perovskite was successfully constructed on the top of 3D perovskite layer. This situation realized the efficient GBs passivation, thus reducing the defects in GBs. As expected, the corresponding PSCs with modified perovskite revealed an improved cell performance. The best efficiency reached 19.6%. Especially, the significantly enhanced long‐term stability of the responding PSCs against humidity and heating was remarkably achieved. Such a strategy in this work affords an efficient method to improve the stability of PSCs and thus probably brings the PSCs closer to practical commercialization.     

Silaindacenodithiophene‐Based Fused‐Ring Non‐Fullerene Electron Acceptor for Efficient Polymer Solar Cells

In this work, a new A‐D‐A type nonfullerene small molecular acceptor SiIDT‐IC, with a fused‐ring silaindacenodithiophene (SiIDT) as D unit and 2‐(3‐oxo‐2,3‐dihydroinden‐1‐ylidene)malononitrile (INCN) as the end A unit, was design and synthesized. The SiIDT‐IC film shows absorption peak and edge at 695 and 733 nm, respectively. The HOMO and LUMO of SiIDT‐IC are of −5.47 and −3.78 eV, respectively. Compared with carbon‐bridging, the Si‐bridging can result in an upper‐lying LUMO level of an acceptor, which is benefit to achieve a higher open‐circuit voltage in polymer solar cells (PSCs). Complementary absorption and suitable energy level alignment between SiIDT‐IC and wide bandgap polymer donor PBDB‐T were found. For the PBDB‐T:SiIDT‐IC based inverted PSCs, a D/A ratio of 1: 1 was optimal to achieve a power conversion efficiency (PCE) of 7.27%. With thermal annealing (TA) of the blend film, a higher PCE of 8.16% could be realized due to increasing of both short‐circuit current density and fill factor. After the TA treatment, hole and electron mobilities were elevated to 3.42 × 10⁻⁴ and 1.02 × 10⁻⁴ cm²·V⁻¹·s⁻¹, respectively. The results suggest that the SiIDT, a Si‐bridged fused ring, is a valuable D unit to construct efficient nonfullerene acceptors for PSCs.     

Synthesis and fluorescence characteristics of novel asymmetric cyanine dyes for DNA detection

Sixteen new asymmetric monomethine cyanine dyes have been synthesized and their spectral characteristics and interaction with double stranded DNA have been investigated. The dyes absorb in the region 453–519 nm and have molar absorptivities in the range 37.900–93.100 l M^?1 cm^?1. The dyes do not have intrinsic fluorescence, but in the presence of dsDNA they exhibited a significant enhancement in fluorescence. The most pronounced increase was found for D9, D10, D12 and D16 allowing the recommendation of these dyes as the most sensitive DNA markers. Thermodynamic analysis of cyanine–DNA complexation was carried out using the McGhee & von Hippel non-cooperative excluded site model, and binding parameters have been derived. A hypothesis describing the DNA–dye binding mode has been proposed.     

Three dimensional micromachining on aluminum surface by electrochemical wet stamping technique

We proposed an up–down working mode of electrochemical wet stamping technique (EC-WETS) for three dimensional (3D) micromachining on aluminum (Al) surface. 3D microstructures on a Si mold were transferred on to an agarose hydrogel containing 15% NaNO₃, 2% MgF₂, 1% NaOH and 5% glycerin, which acted as the quasi-solid electrolyte for the electrochemical micromachining. The transferred 3D microstructures on agarose hydrogel were then duplicated onto Al surface through anodic dissolution. The micromachining quality was improved by pulse-potential method dramatically with a machining tolerance lower than 200 nm and an average removal rate of 210 nm min^− 1 in the Z direction. This method was proved to be a highly efficient, low cost and green method for 3D micromachining on active metal surface, which would be valuable for the manufacture of microelectromechanical system (MEMS).     

Synthesis,characterization and ethylene polymerization of 1-(2,6-dimethyl-4-fluorenylphenylimino)-2-aryliminoacenaphthylnickel bromides

A series of 1-(2,6-dimethyl-4-fluorenylphenylimino)-2-aryliminoacenaphthylene compounds (aryl = 2,6-di(Me)Ph (L1), 2,6-di(Et)Ph (L2), 2,6-di(i-Pr)Ph (L3), 2,4,6-tri(Me)Ph (L4), 2,6-di(Et)-4-MePh (L5)) was prepared and used to form their corresponding dibromonickel complexes (D1–D5). Both L1–L5 and D1–D5 were fully characterized by FT-IR and elemental analysis as well as NMR measurements in the case of ligands L1–L5. The molecular structure of the representative complex D5 was confirmed by single crystal X-ray diffraction revealing a distorted trigonal bipyramidal geometry around the nickel center. On activation with either ethylaluminium sesquichloride (Et₃Al₂Cl₃, EASC) or methylaluminoxane (MAO), all nickel complexes exhibited high activities up to 9.82 × 10⁶ g of PE (mol of Ni)⁻¹ h⁻¹ for ethylene polymerization. In comparison with the polyethylenes obtained with related Ni pre-catalysts, the polyethylenes obtained in this work possessed relatively higher molecular weights and lower levels of branching, highlighting the significant influence of the remote fluorenyl substituent.