A radicular cyst is the most typical odontogenic cyst affecting the human jaws. A radicular cyst is frequently asymptomatic and is discovered accidentally during a radiological procedure. Radicular cyst most commonly occurs during the third and fourth decades of life. The patient affected by a radicular cyst usually gives a history of trauma, and they may even not be aware of the occurrence of the traumatic episode. Such a case of a Radicular cyst that occurred in a 22-year-old-young female who did not follow up further for root canal treatment was radiographically evaluated in three-dimensional view with the help of cone-beam computed tomography. The radicular cyst is also known by other names, such as a periapical cyst or root-end cyst, as it occurs in the periapical region or the root end of the affected tooth. The radicular cyst is usually asymptomatic and is accidentally discovered by routine radiographic examination. Patients affected by radicular cyst usually complain of swelling in the vicinity of the affected tooth region by such cyst. Some patients may even complain of pain in the affected tooth region if the radicular cyst is infected. Radicular cyst occurs more commonly among males in the anterior maxilla region. The teeth commonly affected by radicular cyst are the ones that are more prone to trauma, including the maxillary central incisor, maxillary lateral incisor, mandibular central incisor, and mandibular lateral incisor. The patient usually gives a history of trauma; some even forget the history of the traumatic episode. Here we report a case of radicular cyst in a 22-year-old-female, who underwent an access opening root canal treatment procedure in a nearby private dental clinic four years back but has not followed further follow-up visits -3.A 22-year-old-female reported a chief complaint of pain in the upper front tooth region for two weeks. History reveals that she underwent a root canal treatment in the upper front teeth region four years back but has not followed up further visits properly. A general examination revealed her vitals are stable. The extraoral examination did not reveal any facial asymmetry. Intraoral examination revealed discoloured tooth 22 and obliteration of the labial vestibule due to intraoral swelling concerning the 22 region. There is also a slight labial tilt of 22 compared to the adjacent maxillary teeth Figure .Further examination revealed a swelling localized on the hard palate on the palatal aspect of access opened teeth 22, measuring about 1.5 x 1 cm. The intraoral swelling extended anteriorly about 1 cm away from the marginal gingiva; medially, the swelling extends 1.5 cm away from the mid-palatal raphe region; posteriorly, the swelling extends 4.5 cm away from the posterior palatal seal area, laterally it extends 5 mm away from the marginal gingiva concerning 13, 14 tooth region. In addition, the intraoral swelling is firm, fluctuant, and tender on palpation  at a slice thickness of 75 micrometres at the level of the apical third of the root region of 22 revealed a well-defined radiolucency measuring about 4.6 mm x 6.6 mm surrounding the apical third root portion of 22. The sagittal section CBCT at a slice thickness of 1.1 mm revealed a well-defined radiolucency measuring about 3.2 x 2.6 mm concerning the apical region of the root of 22 with evident destruction of the palatal cortical plate and a discrete radiopacity measuring 1mm in diameter within the coronal portion of the pulp chamber, suggestive of a pulp stone. The axial section CBCT at 1.1 mm slice thickness at the level of the coronal portion of 22 also revealed a discrete radiopacity within the coronal portion of the pulp chamber in 22, suggestive of pulp stone. The Three -dimensional reconstructed CBCT image also revealed an evident palatal cortical plate destruction concerning 22 Figures -4D.Periapical curettage was done in relation to the periapical region of 22 under infiltration with 2% lidocaine local anaesthesia. Postoperative medications cap. Amoxicillin (500 mg) t.d.s for a week and Tab. Ketorolac 10 mg b.i.d were prescribed for three days. The patient refused root canal treatment in 22.The excised specimen was sent for histopathological examination Figure . HistopaThe patient was relieved from tooth pain, and no swelling recurred on the hard palate in the 22 region.The word “cyst,” which is derived from the Greek “Kystis,” means “sac or bladder.” A cyst is a diseased hollow pathological cavity bordered with epithelium that grows in a centrifugal, expansive manner . The radThe blood vessels of the pulp are cut off at the level of the apical foramen of such recently traumatized teeth resulting in ischemic infarction . The epiChen et al. histopathologically analyzed 232 cases of radicular cyst retrospectively and stated that 179 cases (77.2%) revealed chronic inflammatory infiltrate, 94 cases (40.5%) revealed dystrophic calcifications, 72 cases revealed foamy histiocytes (31.0%), 57 cases revealed haemosiderin (24.6%), 54 cases revealed cholesterol clefts (23.3%), 44 cases revealed foreign bodies (19.0%), 22 cases revealed bacterial colonies (9.5%), one case revealed Odontogenic epithelial rest (0.4%) .Kadam et al. recommended that the treatment of radicular cysts includes conventional nonsurgical root canal therapy when the lesion is localized or surgical treatment like enucleation, and marsupialization (Partsch operation), which involves the incomplete removal of the epithelial lining of the cyst or decompression when the lesion is large. The platelet-rich fibrin clot is placed for faster healing in the periapical region . Larger The radicular cyst is the most common inflammatory odontogenic cyst in human jaws. Patients affected by such infected radicular cysts usually complain of pain and report to the oral physician. A careful history and clinical and radiological evaluation are necessary for patients to decide on treatment planning and efficient management of radicular cyst. In addition to being caused by trauma, radicular cysts can also grow as a result of injury to the periapical tissues beneath the tooth, such as from improper follow-up after a root canal procedure and from an access opening done on the root canal attempted tooth. When the patient has not followed up on further subsequent treatment visits, untreated radicular cysts may result in buccolingual growth of the underlying bone and asymmetric facial features. Radicular cysts are frequent in the tooth-bearing regions of the mandible and maxilla. Lesions accidentally discovered to be smaller during a radiological evaluation do not show any symptoms. Large lesions cause discomfort and agony because they subsequently become infected. When the damaged area of the cyst is palpated, it has a variable consistency such as firmness, when the cortical plate is intact or fluctuant, and if the radicular cyst has destroyed the cortical bone. Such infected radicular cyst can be better radiologically evaluated three-dimensionally with the help of CBCT than conventional intraoral periapical radiographs, which do not reveal the exact side of perforation of the cortical plate caused by expansion of the cyst. A CBCT is essential for the three-dimensional visualization of the radicular cyst. CBCT has an added advantage of high spatial resolution that helps to delineate the side of cortical plate destruction caused by radicular cysts and aid in definitive treatment planning.


In conclusion, there are significant differences in the processing performances between different tuber crop starches. For the preparation of RMDs, potato starch seems to be superior to sweet potato and cassava starches. These attributes lay the foundation for considering RDs and RMDs as suitable components for liquid beverages, solid dietary fiber supplements, and low glycemic index (low-GI) products.The anti-digestibility of resistant dextrin (RD) and resistant maltodextrin (RMD) is usually significantly affected by processing techniques, reaction conditions, and starch sources. The objective of this investigation is to elucidate the similarities and differences in the anti-digestive properties of RD and RMD prepared from three different tuber crop starches, namely, potato, cassava, and sweet potato, and to reveal the associated mechanisms. The results show that all RMDs have a microstructure characterized by irregular fragmentation and porous surfaces, no longer maintaining the original crystalline structure of starches. Conversely, RDs preserve the structural morphology of starches, featuring rough surfaces and similar crystalline structures. RDs exhibite hydrolysis rates of approximately 40%, whereas RMDs displaye rates lower than 8%. This disparity can be attributed to the reduction of α-1,4 and α-1,6 bonds and the development of a highly branched spatial structure in RMDs. The indigestible components of the three types of RDs range from 34% to 37%, whereas RMDs vary from 80% to 85%, with potato resistant maltodextrin displaying the highest content (84.96%,  Dietary fiber has received considerable attention due to its positive effects on the prevention and/or treatment of type 2 diabetes, cardiovascular disease, intestinal disorders, and related complications ,2. Dieta2SO4), heating temperatures (≥130 °C), and extended heating times (≥60 min) [Generally, products of starch dextrinization conducted under specific conditions, including dry heat, thermal-acid, and microwave methods, may be resistant to enzyme digestion ,5. RD, o≥60 min) ,10. In t≥60 min) . Namely,≥60 min) . Thus, sratures ≥0 °C, and≥60 min) . The fur≥60 min) ,16. RDs Solanum tuberosum L.), cassava (Manihot esculenta L.), and sweet potato (Ipomoea batatas L.) are the most common tuber crops grown globally, and previous studies have fully reported the molecular structure behavior and changes in product properties during the preparation of RDs and/or RMDs from potato, cassava, and sweet potato starches [Tuber crops are widely cultivated globally, with high starch content and relatively simple extraction methods. Therefore, tuber crops can provide sufficient raw materials for the large-scale production of RD and RMD. Potato , cassava (Manihot esculenta L.), and potato (Solanum tuberosum L.) starches were obtained from Liangrun Whole Grain Food Co., Ltd. . Glucose content kits (GOPOD) were purchased from Jiancheng Bioengineering Institute . Thermostable α-amylase  and amyloglucosidase  were purchased from Macklin Biochemical Technology Co., Ltd. . α-Amylase  was purchased from Yuanye Bio-Technology Co., Ltd. . All other chemicals were of an analytical grade.Normal sweet potato . The pH was adjusted to 6.0 by using 0.1 M of NaOH, thermostable α-amylase  was added and stirred , and then the pH was adjusted to 4.5 using 0.1 M of HCl, and amyloglucosidase  was added and stirred . The final product was concentrated and the supernatant was added to 4 times the volume of liquid 95% ethanol. The sample was left to rest for 4 h and the precipitate was dried to constant weight to obtain the RMD [The RD was dispersed in water . The sample was dispersed on the sample holder and sprayed with gold by an ion sputtering apparatus, and the magnification was adjusted to 2000× or 3000× to observe the morphology .m/m), and then the mixture was pressed into flakes. Finally, the samples were scanned at 4000 to 400 cm−1, with 32 scans and a resolution of 4 cm−1 [An infrared spectrogram was obtained using FTIR . The sample was accurately weighed and mixed with potassium bromide at a ratio of 1:100 , and the sample, after deuterium exchange was dissolved in D2O (99.9%) with a final concentration of 10% (w/v). The analysis was performed by a NMR system  at 25 °C. Subsequently, 1H spectra were collected in 32 separate scans with a scan width of 16 ppm and a delay time of 1 s. Tetramethylsilane at 0 ppm was used as an internal reference.The types of glycosidic bonds in the RDs and RMDs were determined by the method of Bai et al. . The samm/v) and then apparent viscosity measurements were evaluated using a Rapid Visco Analyzer . The specific reaction procedure was referenced from Li et al. [The sample was dispersed in water  and a thermogravimetric analyzer . The sample (2 mg) was mixed with distilled water (6 μL) in a DSC aluminum pan. Prior to the analysis, the pan was sealed and allowed to equilibrate at room temperature for 12 h. Subsequently, the analysis involved heating the sample from 30 to 100 °C at a rate of 10 °C/min, with an empty pan serving as a reference. The resulting heat flow curve was then recorded . A thermg for 10 min. Then, the supernatant (10 mL) was heated at 105 °C for 4 h [The sample (0.4 g) was suspended in deionized water (20 mL). The solution was heated at 25 °C for 30 min and centrifuged at 11,600× −1·L and pH 6.0 were used to suspend the sample of 0.25 g (constant weight). Subsequently, a thermostable α-amylase (60 U/mL) sample of 1.0 mL was added and stirred well , the resulting mixture was cooled to room temperature, and the pH was adjusted to 4.5 using 0.1 M of HCl. Then, an amyloglucosidase (100 U/mL) sample of 1.0 mL was added and stirred . Finally, the mixture was inactivated at 100 °C for 10 min and adjusted to a final volume of 100 mL. The glucose content of the sample was determined using the DNS colorimetric method.The determination of the indigestible ingredient content was conducted following Matsuda’s method with some modifications . InitialThe in vitro digestibility of the sample was determined using Englyst’s model with slight modifications. The sample (0.20 g) was added into 20 mL of 0.5M sodium acetate buffer (pH = 5.2), and the suspension was gelatinized in boiling water for 30 min. After cooling at room temperature, 5 mL of mixed enzyme liquids (containing 290 U/mL of pig pancreatic α-amylase and 20 U/mL of amyloglucosidase) were added and placed in a constant-temperature water-bath shaker at 37 °C, and the mixture was fully shaken at 190 rpm. The glucose contents were determined by the GOPOD kit at 20, 60, 90, 120, 150, and 180 min, the hydrolysis rates were calculated, and the starch hydrolysis data were fitted to a first-order equation .(3)Hydrt is the concentration of the product or reactant at time t, C∞ is the corresponding concentration at the end point, and k is a pseudo first-order rate constant. Cpost hoc test (p < 0.05). All experiments were conducted in triplicate and the results are expressed as the mean ± standard deviation. OriginPro 2023b  was used for the data visualization. Statistical analyses were performed using SPSS 25  with ANOVA, followed by Duncan’s The morphological characteristics of the samples were shown in −1 were different, and the band should be attributed to the affinity of water molecules within the starch molecules [−1. Based on the morphological analysis, these changes are easy to understand. The peak intensities of all RDs and RMDs at 928 cm−1 differed from their respective counterparts in natural starches. The dextrinization process led to a decrease in the number of α-1,4 glycosidic bonds, which was the primary reason for the formation of anti-enzyme digestion properties in RDs and RMDs. This decrease can be explained by the reduction in the molecular weights of RDs and RMDs, as well as by the transglycosylation process, where α-1,4-glycosidic bonds were replaced by other bonds. The transglycosylation process may be one of the main reasons for the decrease in the digestibility of RDs and RMDs [−1/1022 cm−1 and 1022 cm−1/995 cm−1) when comparing RD to starch, suggesting changes in the molecular composition or structure. The observed changes included the disruption of the short-range ordered structure caused by the thermal-acid reaction. Furthermore, the ratio of the amorphous polymer structure to ordered polymer structure in the starch was decreased after this reaction.The FTIR spectra of RDs, RMDs, and natural starches revealed differences in their molecular structures , which colecules . Meanwhiand RMDs ,21. Undeand RMDs . The anaBy analyzing the XRD patterns of the starches, RDs, and RMDs in 1H NMR spectra of the RDs and RMDs, not only α-1,4 and α-1,6 glycosidic bonds were found, but also new bonds or linkages were observed, formed as a result of starch hydrolysis, denaturation, glycosylation, and repolymerization processes. They included 1,6-anhydrous-β-D-glucopyranose, α-1,2, β-1,2, β-1,4, and β-1,6 linkages, each appearing at distinct chemical shift positions. These findings are consistent with the previous research on RDs and RMDs, although there may be slight variations due to the differences in the preparation methods employed [Nuclear magnetic resonance hydrogen spectroscopy was used to identify the types of glycosidic bonds in both the RDs and RMDs. As shown in employed . In the employed , stronglemployed .The digestibility and potential applications of RDs and RMDs were greatly influenced by their molecular structures. The indigestible components of RDs and RMDs were generated through dextrinization, and notably, RMDs underwent further purification via α-amylase treatment, leading to a decreased proportion of α-1,4 glycosidic bonds. Despite the presence of numerous α-1,4 linkages in the RDs and RMDs, their resistance to enzymatic digestion remained notably high, likely due to the highly branching structure of the RDs and RMDs .m/v) [The pasting property curves of starches, RDs, and RMDs were shown in m/v) .There were no phase transition peaks observed in the prepared RDs and RMDs A. This pp < 0.05), when the samples were converted from RD to RMD. The increased solubilities of RMDs indicated that the starches were broken down into smaller compounds during the pyrolytic conversion, while the α,1–4 and α,1–6 bonds in the RDs were hydrolyzed by α-amylase and amyloglucosidase. These enzymatic actions resulted in a higher proportion of oligosaccharides, a lower degree of polymerization, and consequently, higher water solubilities [The solubilities and indigestible ingredient contents of the RDs and RMDs were shown in bilities . On the bilities ,41.2 values exceeding 0.9, except for the potato resistant dextrin. Additionally, our observations revealed that, among the three starches, potato starch displayed the slowest digestion rate, potentially attributed to its crystalline structure. Previous research has indicated that starches with a B-type crystalline structure tend to have a slower hydrolysis rate than to those with an A-type structure [The hydrolysis rates of starches, RDs, and RMDs were shown in tructure . The raptructure .All RDs and RMDs contained substantial quantities of indigestible components, primarily attributed to the dextrinization of starches during thermal-acid treatment. This process resulted in the creation of spatial resistance sites at the enzyme’s active site and the formation of glycosides with β-1,2 and β-1,4 bonds derived from α-1,4 bonds, among other structural modifications. These alterations rendered the RDs and RMDs less susceptible to the activity of digestive enzymes, contributing to their reduced digestibility . The qua1H NMR and FTIR spectra revealed a reduction in α-1,4 glycosidic bonds during the reaction, accompanied by the formation of new glycosyl links, including α-1,2, β-1,2, β-1,4, and β-1,6 bonds. The indigestible components of the three types of RDs ranged from 34% to 37%, whereas RMDs varied from 80% to 85%, with potato resistant maltodextrin displaying the highest content (84.96%). All RDs and RMDs exhibited favorable thermal stability (<200 °C) and high solubility (>60%). These properties provided a theoretical foundation for the application of RD and RMD in various food products, including, but not limited to, cookies, low-glycemic-index reconstituted rice products, and dietary-fiber-enriched beverages. In addition, the forthcoming research will center on evaluating the effects of incorporating RDs and RMDs into starch-based foods, including their effects on pasting, aging, rheological properties, and digestive behavior. We will also investigate the potential for directed dextrinization to enhance the levels of indigestible glycosidic bonds. This research will play a pivotal role in advancing sweet potato (Ipomoea batatas L.), cassava (Manihot esculenta L.), and potato (Solanum tuberosum L.) industries, contributing to their high-quality growth.The structures of RDs and RMDs were significantly different from those of natural starches, exhibiting disordered spatial arrangements, destroyed crystal structures, and a loss of the ability to form pastes. While the microstructure of the RDs still retained starch-like characteristics, the RMDs developed surface irregularities and porous structures. Meanwhile,


One in five women in the UK are survivors of rape and sexual assault, and four in five women will give birth. This implies that a substantial number of women experience rape and sexual assault before pregnancy. We highlight and explore the voices and lived experiences of survivors during pregnancy and birth, to better understand the relationship between sexual violence, biomedicine, and pregnancy and to inform maternity care practice.This qualitative research took an intersectional feminist approach. We conducted in-depth individual interviews in England with fourteen women who self-identified as survivors of rape or sexual assault, and who had experienced pregnancy and birth after the assault. We conducted open line-by-line coding of the interview transcripts, and identified key themes and sub-themes inductively.Three themes help summarise the narratives: control, safety and trauma. Maintaining a sense of control was important to survivors but they often reported objectification by healthcare staff and lack of consent or choice about healthcare decisions. Participants’ preferences for giving birth were often motivated by their desire to feel in control and avoid triggering traumatic memories of the sexual assault. Survivors felt safer when they trusted staff. Many participants said it was important for staff to know they were survivors but none were asked about this. Pregnancy and birth experiences were triggering when they mirrored the assault, for instance if the woman was prevented from moving. Many of our participants reported having unmet mental health care needs before, during or after pregnancy.Survivors of sexual violence have specific maternity care needs. For our participants, these needs were often not met, leading to negative or traumatic experiences of pregnancy and birth. Systemic biases and poor birth experience jeopardise both psychological and physical safety. Funding for maternity and mental health services must be improved, so that they meet minimum staffing and care standards. Maternity services should urgently introduce trauma-informed models of care. This research focuses on the experience of pregnancy and birth for survivors of rape and sexual assault (RSA). RSA is common: In the UK, 20% of women have experienced sexual assault . In a saRape is legally defined as a person intentionally penetrating another’s vagina, anus or mouth with a penis, without consent; sexual assault is defined as intentional sexual touching without consent . RSA oftThe concept of ‘rape culture’ frames rape as a violent crime and tool for maintaining patriarchy i.e. an overarching system of power founded on men’s dominance, women’s subordination and ‘men’s ownership and control of women’s reproductive powers’ , 18, ratYoung’s  concept Experiences of pregnancy and birth can be negative for many individuals. In an Australian study of 933 women, 866 were followed up to 6 weeks postpartum; 45.5% of this group reported that they had experienced a threat to themselves or their baby, and had experienced fear, hopelessness or horror during birth . In a smDespite the importance of the topic, there have been few qualitative studies exploring the experience of pregnancy and birth for survivors of RSA. In one UK study, nine in-depth interviews were conducted with women who had lived through childhood sexual abuse (CSA); it explored their experience of pregnancy and birth, and included themes on loss of control, pain, encounters with strangers, triggers and re-enactment, or mirroring, of abuse through the way in which intimate procedures were conducted . Most reThe experience of pregnancy and birth, and listening to pregnant people’s lived experiences and voices, is not just desirable, but essential to providing safety within maternity care - in the UK and worldwide. The 2017–2019 UK and Ireland national inquiry into maternal deaths and mortality (known as MBBRACE) found that Black women are more than four times and Asian women almost twice as likely to die in the perinatal period than white women. The inquiry emphasised that addressing intersecting structural biases is fundamental to the prevention of maternal mortality . The subThe duty to uphold dignity is encoded in professional standards for doctors, nurses and midwives , 36. In Studies that have been conducted in the UK focussed on survivors of CSA and their later pregnancy experiences. There is a lack of research on pregnancy and birth experiences in the NHS for rape and sexual assault survivors. In this study we focused on the experiences of women who survived RSA without becoming pregnant due to the assault, then later in life experienced pregnancy and birth. We aimed to highlight and explore the voices and lived experiences of survivors during pregnancy and birth, to inform better maternity care services and practice, and to better understand the relationship between violence, biomedicine, and pregnancy.The study was undertaken in England during June and July 2021. Interviews took place online, in participants homes or, in a few instances, at a rape crisis centre in North England. Participants were located across England.This qualitative research took an intersectional feminist approach. We conducted in-depth interviews with survivors of RSA, aiming to explore their lived experience of pregnancy and birth. Feminist principles included flattening hierarchies, an ethic of care, reciprocity, reflexivity and relational interviewing –43. An iTwelve rape crisis centres in the East of England (4), South East (2), East Midlands (1), West Midlands (2) and North West (3) supported the research. Other supporting organisations included ‘The British Pregnancy Advisory Service Centre for Reproductive Research and Communication’, Decolonising Contraception and Birthrights. Our advert contained a research description and contact details. Supporting organisations shared the advert via their networks, social media channels and newsletters. We shared the advert in our networks. Participants volunteered to take part by contacting RL, who screened them against inclusion criteria: over 18 years old, living in the UK, self-identifying as survivors of either rape or sexual assault at any age, experienced pregnancy and birth after the assault. Participants of any gender, ethnicity, socio-economic grouping or location within the UK were included. Interested participants were sent the participant information sheet. Most were available for a phone call to discuss the research and establish a relationship. Decisions regarding the interview location, time, date and length were the participants’ choice. Participants digitally signed the consent form prior to interviews. Participants were encouraged to contact RL if they had further questions. All participants were compensated with a £5 voucher of their choice. Fourteen women participated in the research. All had given birth in the UK, except one person who had given birth elsewhere.Fourteen people agreed to participate in the research following the initial recruitment effort. Ten interviews were held in person and four were held via Zoom video call with end-to-end encryption enabled. Interviews were held via Zoom either at the participant’s request or due to travel limitations. Eight of the in-person interviews were held in the participant’s home, and two were held at a rape crisis centre. Only the participant and RL were present for interviews.RL conducted and audio-recorded all interviews. Interviews were 60 to 135 minutes long, with most lasting approximately 90 minutes. The interviews explored themes including pregnant selfhood, narratives of survival, interactions with clinicians and networks of support. Interviews began with broad, less sensitive questions such as ‘Can you tell me a little about your life at the moment?’Follow-up questions explored topics raised by participants. We present below the responses to these questions which appeared across multiple interviews.Data were anonymised. Participant information and data were stored separately and securely. RL transcribed ten interviews and an external agency transcribed four of them. RL checked each transcript for accuracy and used NVivo12 to code transcripts iteratively during data collection. RL familiarised herself with the data by transcribing and reading through transcripts, reviewing field notes and discussing data with the research team. Open line-by-line coding formed a series of codes which ranged from descriptive to conceptual. Second level coding then brought together open codes. This approach allowed themes to be derived inductively. Themes were reviewed and discussed by RL and ML to identify three key themes. Two to three connecting subthemes were developed under each key theme. Feminist epistemology and intersectional feminism informed analysis, exploring how gender interacts with power structures such as neoliberalism and racism, and rooting knowledge in the lived experience of participants .This paper was part of RL’s Masters dissertation, supervised by ML and CM. RL is a junior doctor training in obstetrics and gynaecology. ML is an Assistant Professor and CM a Professor at the London School of Hygiene and Tropical Medicine (LSHTM). RL used reflexive approaches including journaling, developing field notes, analysing power dynamics with participants during interviews and seeking to reduce hierarchies, and discussing reflections on power and positionality with others, including the co-authors. She approached interviews as a relational process, where accounts were co-created. She aimed to build reciprocity, trust and solidarity with participants, irrespective of whether interviews were in person or online, including answering interviewees’ personal questions.To maximise usefulness of the study, we took steps to ensure different voices were incorporated and used rigorous analytical methods to fairly represent the interview data. In addition, the themes we identified align with and expand on existing evidence from other sources. For these reasons, we would anticipate similar findings would be yielded from other, similar, settings if our study were replicated elsewhere in the UK and possibly more widely. In this sense the research is credible, confirmable and transferable.This study was approved by the LSHTM ethics committee . Throughout the research, we prioritised participants’ wellbeing. RL undertook online training on working with sexual assault survivors, and developed a protocol in advance to handle any cases of participant distress.Participants were from mixed socioeconomic backgrounds. All reported current or past heterosexual relationships and one spoke about her lived experience as a Black woman. Participants were not explicitly asked to define their gender identity, however nine referred to themselves as women. It is possible that some participants may identify in other ways. Of the fourteen participants, five were survivors of rape and sexual assault during childhood, seven during adulthood, and the final two described RSA during both childhood and adulthood.Three linked themes help summarise the narratives: (1) Control – including sub-themes of objectification and birth preferences; (2) Safety, with sub-themes including trust and disclosure; and (3) Trauma, including sub-themes of triggers, mental health and multiple traumas.‘I know that birth is uncontrollable, but what I can control of it, I want to.’ Control and consent came up frequently:Control and consent were described by participants as important in their experiences of pregnancy and birth, linked to the concept of lost bodily autonomy. Survivors expressed an understanding that birth carries clinical risk and is an unpredictable process. However, they wished to exert as much control as possible: [If] you’ve been in a situation where you’re so vulnerable, and you’ve lost control of your body and your rights to your body and your rights to say no, or even, in my case, my rights to wear pyjamas to bed. To be able to have the control to go, I’d like this to not happen, is really important.‘And there was just suddenly all these people, and all these hands, and nobody was really saying ‘I’m gonna do this, I’m gonna do that’ it was all just kind of like that.’Only two participants reported that they gave informed consent throughout their care. Five survivors described experiences where no attempt was made to gain consent. For example: ‘And they said, ‘The student’s going to examine you.’ And that’s when I thought, well I put in my notes that I don’t want her to. But by that point I felt a bit, sort of… bit frightened, really. And so, she examined me…’.Participants often said that they had been told they would be examined, rather than asked whether they consented to be examined: Participants were not always listened to. One participant was a Black woman and had presented in pain repeatedly before she was investigated and treated for appendicitis during pregnancy. She identified the role of racism:[T]here’s just been a whole load of, I guess, like fresh awareness around just Black women, women of colour not being taken seriously. And I just had never, probably ignorantly, just known that that was a thing. Just had not realised that… when we do present in pain, people were just like… either you’re not in pain, or you’re not in as much pain as you think you are.In accounts where a discussion did occur, some described a sense of false choice or coercion. Participants explained how vaginal examinations were presented as compulsory in order to access other elements of care:And the midwife said to me, she was like, ‘You don’t have to have an internal exam. But the doctors in theatre, male doctors in theatre, won’t admit you unless I know how many centimetres you’re dilated. So it’s a case of you don’t have to have this exam but if you don’t, they’re not going to take you down for the C-section’. So it’s like, I do have to have it then don’t I?‘didn’t have a choice anymore’ when she was told her baby was distressed.Participants shared how the baby’s needs may be prioritised above the pregnant person’s, reducing women’s control over decisions. For instance one woman who declined a Caesarean-section earlier in labour said she felt she ‘object’ and ‘vessel’ to describe their experiences. Three different survivors spoke about being made to feel ‘like a piece of meat in butcher shop’, ‘like a greenhouse’, and as if they were not ‘in the room’. Another reported that she felt ‘positioned as obstructive’ and ‘…just this annoying thing that surrounded the important part’. In some cases, the objectification was more subtle:Many participants felt objectified by healthcare staff, commonly using the words [W]hen she [baby] was delivered, he [partner] was running round the operating theatre like she was the FA cup, that’s how I thought of it. And they were saying, show her the baby, show the mum the baby. And in the end the midwife had to grab her and pull her off him and put her next to me so I could see her….‘begged’ for a Caesarean section over several days, when a new consultant arrived:In another account, a participant was becoming increasingly unwell. She had [H]e said to me, I’m not being funny and I don’t want you to take this the wrong way, but your baby’s not my patient, you’re my patient. And at this point she’s a parasite and she’s hurting you, so we need to get her out. And I’d never met him before but I trusted him from that moment, straight away.Whilst control was important to all participants, they held different views on what kind of birth would make them feel most in control. Four survivors expressed a preference for Caesarean section. Reasons for this included hoping to avoid vaginal examinations and tearing, to know what would happen in advance, to give birth calmly and to avoid an emergency or an influx of people into their birthing space. One woman’s first birth was vaginal and her subsequent birth was by Caesarean section:And the funny thing is, I did feel more in control in a way with the Caesarean. Because they explain everything to you, it’s all very predictable, isn’t it, I suppose in a way that birth isn’t. So, you know, they say, ‘We’re going to do this now, and this will happen’. And they do it and it happens. And- not like birth, where you go in and it’s like… going through a minefield with your eyes closed.By contrast, six survivors spoke about the importance of a non-medicalised birth. They valued, for example, the opportunity to give birth in a room with just a few people in it, without medication that might render them immobile, and without the sense of objectification caused by having things done to them by healthcare staff. The participant who gave birth outside the UK echoed comments about control made by other participants who had given birth in the UK, when she said:[I]f you just think of a Caesarean section, you can’t- you can’t do or be anything that you are, because essentially, they are performing surgery on you. And they dictate how your body should lie on the table, who is going to perform what on your body. You have no say. That’s what I feel like, for me, is like the handing over of my body. This erm… complete loss of control, essentially.negotiating’, ‘manoeuvring’ and ‘fight[ing]’, or using their social status, education, or skills. Others employed internal coping mechanisms: ‘I didn’t really connect with my pregnancies. I wasn’t- I was quite good at being pregnant because it didn’t really… there was a bump. And then there was a baby. There was no baby before she was there and she was on me.’.Survivors described holding these differing birth preferences for similar reasons: to maintain a sense of control, or to avoid the birthing process from triggering memories of the assault. Many participants described strongly advocating for their birth preferences: they described ‘Participants said they wanted to give birth safely. However, they spoke about safety holistically rather than only in relation to physical risk, referring also to the environment and the people around them. One survivor contextualised the importance of safety:Like, if I’m around people that get me and accept me, then I feel safer… I don’t have to constantly explain myself or be like, oh, that’s not what I meant. Or, like, so it means that I can be calm. And I guess in a kind of cavewoman sense, if I’m not thinking about all those things, I’m gonna see the sabre-tooth.She later explained that the sabre-tooth symbolised danger and trauma. She wanted to reduce her mental load so that she would spot danger approaching. Other participants also mentioned primal or intuitive needs when discussing safety.Survivors felt safer if they trusted the maternity staff looking after them. Only three participants reported seeing the same healthcare provider repeatedly during their antenatal care. Survivors described developing trust in a doctor or midwife when they gave consistent, personalised information, shared the same lived experiences, for example as a Black woman, or showed an interest in knowing them as an individual, by reading their notes, listening, or using their name:I’m talking in a kind of wishful thinking way, because I appreciate that it’s- it would be impossible really to do it. But I think I would’ve felt safer, more trusting of my doctor if he’d known my name, or if he was even able to give the illusion that he knew my name. And- and feeling like he’s genuinely interested… in what I want from- from my pregnancy and from my birth. He’s genuinely interested in my wellbeing.‘It makes it quite difficult to feel like a person, rather than kind of like a number in the system, to really feel seen.’Almost every survivor described wanting to be seen as a whole person and ideally to interact with a healthcare professional who reciprocated by sharing something of themselves. This was challenging in the context of systematised healthcare and objectification: ‘[If] I don’t tell somebody that, then they don’t know me.’ When another survivor expressed anxiety about vaginal examinations, the midwife responded: ‘well, put it this way, if you’ve managed to get a penis in there to get yourself pregnant, you’ll be able to have this examination done.’ This was not a safe space to disclose.Some survivors felt that maternity staff needed to know their status as survivors in order to care for them properly. One participant described that no one asked whether she was a survivor, despite signs. She felt they ignored her because talking about sexual assault was too difficult. Yet, she saw her status as a survivor as an essential part of her history: Nine participants realised their sexual assault was relevant to pregnancy and birth either before or early on in their pregnancy. The remaining five came to realise this in retrospect. None of the participants were asked whether they were survivors and the main reason for choosing not to disclose was that the healthcare provider did not ask. Five people disclosed during their pregnancy or labour. Of this group, three disclosed in the context of explaining their birth preferences for either a Caesarean section or midwife led care. Despite it being documented in their notes, all three reported having to disclose repeatedly in order to explain their preferences. One described this vividly:[I]t just felt like I was pulling the top layer of my skin off over and over again and leaving my nerves exposed. And nobody ever treated it, they just kept pulling my skin off, and my nerves were just exposed. So every time I went in there and just go, well, this happened, and really quickly tell them this really massive thing.‘This was ten years ago, why are you bothered?’.Participants reported that reactions to disclosure reflected discomfort, inadequate knowledge of how to respond and sometimes disbelief. One was asked ‘hands off’ and avoid triggering her. She went on to share her positive birth experience:Another participant disclosed but also described not having insight into the relevance of her sexual assault at the time. During her second labour, the midwife explored what had been difficult about her first birth, and she disclosed within this broader conversation. This survivor later connected her disclosure with her midwife’s decisions to be I was like, filled with romance about how wonderful birth is and how amazing I am because ‘Look what I’ve just made’. And I was so proud of myself that I decided I was going to do it again… Third time round I was a surrogate….Events during pregnancy and birth may cause retraumatisation by triggering past trauma from rape or sexual assault. One participant highlighted that her birth was traumatic because the behaviour of maternity staff mirrored that of her abuser, rather than because of medical complications:It was just traumatic- it was just the trapped- it was people sort of, you know grabbing onto your thighs and pushing your legs and doing things with your body that I’ve obviously experienced before under different circumstances and every time it happened just another image in your mind. So you just lay there, like you’re going through it all over again.Two participants said that they wanted more children but had chosen not to. They said they could not risk further trauma by going through another pregnancy and birth.Triggers, both anticipated and experienced, were linked to survivors’ sexual assaults and other lived experience as women. They influenced their birth plans:I don’t want men involved in my antenatal care or labour care… when I’m in a space where I’m going to feel vulnerable anyway, I just don’t want to hear men’s voices in my ear, even if they’re nice people.‘He was doing an internal examination and I told him, stop. And he didn’t. And I told him stop. And he didn’t. And I shouted at him to stop. And he didn’t. And he only stopped when my husband said stop…’.Seven survivors found men triggering. For two it was important that men were not involved in their care. Some survivors saw the potential for harm without intent. However, another recounted one vaginal examination, which she named as sexual assault: Four participants felt anxiety during pregnancy. After birth, two reported low mood, and a further two had symptoms of psychosis. Many described symptoms associated with post-traumatic stress disorder (PTSD) during their pregnancy or birth, which included flashbacks, nightmares, a sense of being ‘in’ the trauma, avoidance of trauma related stimuli, or finding their memories muddled between their birth and sexual assault. Three participants did not describe any mental health symptoms; some said they had processed their trauma before becoming pregnant.‘…she was amazed that I’d been able to have sex to get pregnant as a survivor of rape… She just didn’t believe me that- that I could possibly have been raped and then have a healthy sex life thirteen years later.’Only one survivor saw a mental health specialist ‘pre-crisis’ under the NHS; she was seen by a nurse who expressed disbelief that she was a survivor: Another participant took an overdose because her mental health declined during pregnancy and she could not cope with her symptoms. She was taken to a psychiatric hospital:[N]o one had said but it was PTSD… constant flashback[s]… nightmare[s] all the time… And then when you’re pregnant, all the thing[s] they have to do, which… triggers some of the flash back- a[s] well. So [pause] yeah, that was really hard. Even though I really wanted this baby.One woman’s abuse began shortly after she gave birth to her first child. In her following pregnancy the delivery suite was triggering. She was referred to the perinatal mental health team early in her second pregnancy, but was not seen until 8 months post-partum. In the absence of the mental health team, her midwife provided significant psychological support, and offered her the option to give birth elsewhere. By contrast, another woman’s health visitor missed the opportunity to support her:So I- I- told her that I’m not feeling too well, I’m- sometimes I think I might… I’m gonna die or I had really negative thoughts. They said, ‘Okay, just wait a little bit. Maybe it’s just your hormones, you just gave birth’. And I think after that, I started to think- and I was really worried that they would take my [baby] away from me. And after that, even if I didn’t feel well I just said, ‘I’m alright.’‘…we have got also Brexit during all these things. So I was afraid that- oh, all these things come back to me because I’m not English.’She was not able to access further support until her child was two years old. As she waited for mental health services, the same participant described fear that her leave to remain was under threat: Several survivors felt that mental health services did not meaningfully engage in treating trauma caused by sexual assault. Instead, they were referred to rape crisis centres, which are charities with long waiting times. They wanted a service that connected sexual assault, maternity and perinatal mental health care.‘somebody wanking down the phone’, another mentioned avoiding walking at night. Some had lived through other trauma, including child abuse, being in the care system, domestic violence, police brutality, abduction and miscarriage. They navigated challenges, such as moving house, family disputes, illness or deaths, and financial hardship. One participant summarised: ‘I’ve never had a period of time in my life before my children came along where everything was okay. For any length of time longer than just getting through the day.’Participants described layers of trauma experienced during their lives. Sexual harassment was common: on the morning of the interview, one survivor described a call from a private number with ‘…it was just- and similar to, you know, what- the assault and things. It was- it was like you’re there for anybody’. Among our participants there was no specific difference evident between those who survived sexual assault as children or adults. However, only people who survived childhood sexual abuse expressed a sense that the trauma they experienced during birth fit in to how things had always been for them. Not all of the sub-group described feeling that way.For one survivor, her sense of vulnerability and the lack of consent during labour were consistent with her sexual assault, as both a child and adult, up to that point: This study shows how neglecting to take women’s experiences of rape and sexual assault into account during maternity care can lead to negative or traumatic experiences of pregnancy and birth. Women are confronted by the consequences of gender-based violence throughout the life course, including during pregnancy and childbirth. Participants’ accounts depict women’s positioning within a health system that often reinforces patriarchal structures and norms. Survivors carry the impact of past traumas into pregnancy and birth and prioritise retaining a sense of control and feeling safe. These priorities are often not elicited, explored, or addressed by those responsible for their care.Informed consent is a professional standard, ensuring women retain bodily autonomy and dignity , 36. PreBeing seen as a person with their own identity was important both to the process of consent and in building safety through trusting connections with maternity care staff. Continuity of care can facilitate trusting, reciprocal relationships . AlthougIn line with previous literature , 7, 10, The 2017-2019 national MBBRACE report stated that addressing ‘structural biases affecting women’s care on the basis of their pregnancy or the potential to become pregnant is fundamental to preventing maternal mortality…’ . These sIn this study we were not able to assess whether there are differences between diverse groups of pregnant people. There may be important additional issues to consider for different marginalised groups, such as disabled people. Factors such as race, sexuality and class interact with cultural differences, and social phenomena and so may produce additional findings.A substantial proportion of women who become pregnant and give birth in the NHS will be survivors of rape and sexual assault. Healthcare professionals must take this into account by ensuring they obtain informed consent, provide choice and enact simple changes to build trust, for example by using people’s names rather than generic terms such as ‘mum’. Maternity care leads should ensure teams are trained on trauma and RSA, as part of working towards a trauma-informed model of care , so thatParticipants in this research had specific maternity care needs as survivors. The current widespread failure to recognise the prevalence and impact of rape and sexual assault produces a healthcare system which does not meet survivors’ needs, risking their physical and mental health.


Electrophorus sp.) are known for their ability to produce electric organ discharge (EOD) reaching voltages of up to 860 V. Given that gene transfer via intense electrical pulses is a well-established technique in genetic engineering, we hypothesized that electric eels could potentially function as a gene transfer mechanism in their aquatic environment.Electric eels  and exposed them to electric eel’s EOD.Some embryos exhibited a mosaic expression of green fluorescence, in contrast to the control group without electrical stimulation, which showed little distinct fluorescence. This suggests that electric eel EOD has the potential to function as an electroporator for the transfer of DNA into eukaryotic cells. While electric eel EOD is primarily associated with behaviors related to sensing, predation, and defense, it may incidentally serve as a possible mechanism for gene transfer in natural environment. This investigation represents the initial exploration of the uncharted impact of electric eel EOD, but it does not directly establish its significance within the natural environment. Further research is required to understand the ecological implications of this phenomenon. Gymnotus electricus, and later revised as Electrophorus electricus by Theodore Gill in 1864 . We conducted the experiments using live animals, ensuring that they were under anesthesia with 0.01% tricaine, in strict accordance with the institutional guidelines. In cases where the animals experienced severe health deterioration during the experiment, we euthanized them under ice anesthesia with 0.01% tricaine.Electrophorus sp.) was purchased from Meito Suien Co., Ltd . The fish was housed in a freshwater tank (90 × 45 × 45 cm) at 27 °C under a 14 h:10 h light: dark photoperiod cycle. To regulate the pH of the tank water within the range of 7.0–8.0, approximately 1.5 g of sodium hydrogen carbonate was added to the fish tank once a week. They were fed a pellet diet  or live goldfish or Japanese loach.The electric eel  and fed a powder diet or live Artemia. Fertilized eggs and embryos were maintained in 0.3% sea salt water.Oryzias latipes β-actin promoter (accession number LC775392). Plasmids were amplified in DH-5α competent cells  and subsequently extracted and purified using the Plasmid DNA Extraction Midi Kit . The DNA solutions were stored at −20 °C until use.The donor DNA used for electroporation was an 8,888-bp plasmid containing the GFP coding sequence driven by the https://www.st-andrews.ac.uk/~wjh/dataview/).The electric eel’s discharge waveform was recorded using the following method. Recording and reference electrodes were constructed by connecting a 99.9% carbon rod  to a lead wire. One of these electrodes was positioned in an experimental tank (60 × 30 × 36 cm) containing a single electric eel, and it served as the reference electrode while being grounded. Additionally, one of the two electrodes was placed on the electric eel’s head as the positive pole, and the other carbon electrode was positioned on its tail as the negative pole. The voltage between the two electrodes was attenuated to 1/500 of the original signal using a High Voltage Differential Probe  and then input into a USB Data Acquisition Module , which was connected to a Windows PC for display and recording. The sampling frequency was set to 20 kHz. The waveform recording and subsequent analysis were conducted using the DataView software  equipped with a suitable filter set . Both brightfield and fluorescent images were captured using a Leica K3C digital color camera, and the imaging process was facilitated with Leica Application Suite (LAS) software. Following the microscopy, the zebrafish larvae that had survived were euthanized using ice anesthesia with 0.01% tricaine solution.https://jasp-stats.org/. A p-value below 0.05 was regarded as statistically significance.The data is presented as the mean ± standard error of the mean. Statistical analyses were conducted using the freely available and open-source software, Jeffreys’s Amazing Statistics Program (JASP), which can be accessed at Electrophorus sp.; gender unknown; approximately 60 cm in total length) as the electric source for our investigation (O. latipes β-actin (actb) promoter as a transgenic indicator  vs. 96.0 ± 3.1% for EOD-/DNA+ (n = 9), P = 0.898; EOD-/DNA- vs. 87.2 ± 14.8% for EOD+/DNA- (n = 9), P = 0.029; EOD-/DNA- vs. 89.6 ± 11.4% for EOD+/DNA+ (n = 15), P = 0.057; n = 12) vs. 0.5 ± 1.1% for EOD-/DNA+ (n = 9), P = 0.986; EOD-/DNA- vs. 2.3 ± 5.5% for EOD+/DNA- (n = 9), P = 0.538; EOD-/DNA- vs. 4.8 ± 6.4% for EOD+/DNA+ (n = 15), P = 0.025; At the outset, we attempted to employ fertilized eggs at the cleavage stages or 1- to 2-day post-fertilization (dpf) embryos for electroporation driven by electric eel discharges. Regrettably, these embryos did not survive, primarily due to yolk sac rupture during electric exposure or other manipulations. Consequently, we opted to utilize 7-dpf embryos, which had advanced beyond the yolk sac stages and exhibited a more robust body structure. In each trial, we subjected 20–49 larvae to the plasmid DNA solution using distinct electric eel discharges, conducting a total of fifteen repetitions . FollowiIn this study, we propose that electric eel EOD facilitates the transportation of DNA into cells from the surrounding water environment. This suggests that electric-based transgenesis might occur not only through artificial electroporators in laboratory settings, but also through living electric organisms in their natural habitats. Previous reports have indicated the presence of 2.68 ng/µl of environmental DNA (eDNA) extracted from the Amazon hydrosphere . The eDNOur demonstration solely pertains to environmental gene transduction in somatic cells, and we have not yet confirmed whether the transgene functions as a heritable factor in offspring. In the case of electroporation using machinery, some studies have reported the introduction of exogenous genes into the germline cells of vertebrates, including fish . Under vEscherichia coli and Paramecium sp (E. coli, machine-based electroporation typically employs discharges exceeding 1 kV cm−1 (E. coli cells. Previous reports have indicated that Paramecium can uptake exogenous DNA through electroporation (Paramecium using established plasmid DNA carrying GFP (Paramecium under our experimental conditions. In a previous study, electroporation into Paramecium was achieved successfully using a discharge of 500 V cm−1 (To validate heritable transgenesis, unicellular organisms are suitable models because they reproduce the next generation through division or budding. We investigated electric eel-based gene transfer using the unicellular organisms ecium sp . However kV cm−1 . In our poration . Therefoying GFP . Regrett0 V cm−1 . Hence, It is important to consider the differences in pulse shapes between electric eel-based electroporation and machine-based electroporation. In many instances, machine electroporation conditions are optimized using square pulses to achieve maximum viability and efficiency . HoweverWe carefully designed the experiment to ensure the consistency of the discharge conditions received by the zebrafish larvae in each trial. However, it’s worth noting that factors such as the pulse shape during prey capture and the precise distance and location between the electric eel and the electroporation cuvette may not be entirely uniform across all trials. To address this issue, we acknowledge the need for improved experimental settings that can minimize variations between trials. One potential approach could involve the use of a machine electroporator capable of delivering consistent and repeatable pulses, similar to the electric eel’s EOD. Additionally, we recognize the potential suitability of employing a generalized linear mixed model as a statistical method in future investigations to account for variability between trials .In our study, we observed a few cases of false positive fluorescence in samples that were exclusively exposed to the EOD or DNA. These signals may encompass autofluorescence in cells damaged by the electric discharge or other factors . In sampThis study offers evidence supporting the idea that electric discharge from electric eels can enhance DNA transformation in zebrafish larvae. Our innovative approach, utilizing live animals as the source of electric discharges, suggests the potential for such discharges to contribute to gene transfer in natural environments. Nevertheless, it is essential to recognize that our research was conducted in controlled laboratory conditions. Therefore, we cannot definitively assert that electric discharges act as a genetic factor in natural settings based solely on our findings. Further investigations are necessary to explore the heredity of electric discharge-mediated transgenesis and to accumulate evidence for its occurrence in natural habitats.10.7717/peerj.16596/supp-1Supplemental Information 1Click here for additional data file.10.7717/peerj.16596/supp-2Supplemental Information 2Click here for additional data file.10.7717/peerj.16596/supp-3Supplemental Information 3The raw data for the numbers of samples used to draw the graphs in Figure 4.Click here for additional data file.


Iridium based C–H borylationcatalysts in particular are established as one of the foremost methodsin the field of C–H functionalization.3 Main group compounds also have been applied as catalysts for areneC–H borylation, with the greater abundance, lower cost, andhigher permitted exposure limits of most main group elements relativeto precious metals one key driver for this research.4 A second driver stems from the fact that main group catalysisgenerally proceeds at a fixed oxidation state thus requiring distinctborylation mechanisms. This can lead to complementary regioselectivityand functional group tolerance to that using transition metal basedcatalysts. However, significant challenges remain in main group catalyzedarene borylation, particularly around expanding the substrate scopeand generating operationally simple methodologies.5 Most systems reported to date use (pre)catalysts that arechallenging to handle (due to their sensitivity to protic speciessuch as H2O) and that are limited in substrate scope tonucleophilic (hetero)arenes  > 1, for reference,2-Me-thiopheneand furan have N ≈ 1.3).6 Identifying a single catalytic system that addresses bothof these challenges is essential for the wider uptake of main groupcatalyzed arene C–H borylation.C–H borylation is anefficient method to generate organoboranes that are powerful intermediatesin synthesis, due in large part to the Suzuki–Miyaura reaction.7 andintramolecular C–H borylation, the reader is directed to recentreviews.8This viewpoint summarizesthe general approaches used to date inmain group catalyzed intermolecular arene C–H borylation. Itis not a comprehensive survey of the area; instead, it focuses onanalyzing common key steps and through this seeks to highlight someof the current challenges and future opportunities in the field. Forstoichiometric (in strong Lewis acid)EAr type process9 and thus can be termedelectrophilic borylation reactions. Inthese, controlling the fate of the byproduct from SEAr,[H]+, is vital.10 Indeed, theeffective sequestering of [H]+ was recognized as crucialeven in the early stoichiometric electrophilic borylation studiesfrom the 1960s.11 The generation of [H]+ as a byproduct also provides a route to using substoichiometricelectrophilic activators in arene borylation. Combining [H]+ with a hydroborane  or pinacolborane(PinBH) derivatives) or another hydridic species can lead to H2 evolution and (re)generate a reactive electrophile for performingfurther C–H functionalization. Virtually all main group catalyzedborylation reactions reported to date rely on this as a key step toclose the catalytic cycle. To facilitate analysis, these reactionshave been divided into two types based on the nature of the electrophilethat effects C–H functionalization. Specifically, it separatessystems based on whether or not a σ-bond metathesis step isrequired to form the target aryl-borane post C–H functionalization.These two classes are discussed separately as they have distinct challenges.For example, approach (i) requires converting a hydroborane into anelectrophile that effects SEAr . This study highlighted a numberof important factors: (i) the need for a robust (toward electrophiles)hydroborane as pinacolborane decomposed under the reaction conditions;(ii) the necessity for the correct anion, with key considerationsbeing low anion coordinating ability and high anion stability. Inthis work the highly reactive nature of the electrophile(s) necessitateduse of the extremely robust [closo-CB11H6Br6]− anion.14 The reactive boron species was termed [CatB(closo-CB11H6Br6)], 1 . The identity of this ligating species, termedL, is a key variable in approach (i) as it has a significant effecton multiple steps in the catalytic cycle.This approach generally uses substoichiometricadditives to convertCatBH (or a derivative) into an electrophile that then effects areneC–H borylation. In our early work CatBH was combined with 5mol % of CatBBr/+ cations,such as 3 L can also be the Brønsted base that deprotonates arenium cationintermediates; (iv) the conjugate acid, [LH]+, then isinvolved in the dehydrocoupling step forming H2 and regeneratingthe electrophile and L. A number of these processes are shown in 16a It shouldbe noted that L also can lead to off-cycle species, such as [CatB(L)2]+ boronium cations , andto substituent redistribution of CatBH to form Cat3B2 and L–BH3.17 Furthermore, in some systems competing reactivity  can occur to generate a “hidden”L in situ which can also play a crucial role.18Subsequent reports from multiple groups utilized CatBH/PinBH inthe presence of exogenous L (which forms a dative bond with the hydroborane)to borylate arenes using a substoichiometric Lewis acid activator t+. Furthermore, a weakly Brønstedbasic L will lead to less exothermic deprotonation of arenium intermediatesbut generate a stronger conjugate Brønsted acid ([LH]+), thereby impacting the energetics of the dehydrocoupling step.The above only consider minima on the potential energy surface; clearly,altering L will impact the energy of the transition state involvedin each step. Thus, it is challenging a priori topredict an optimal L for electrophilic borylation even when ignoringcompeting off-cycle reactivity, e.g., substituent scrambling and Lbinding to the activator. Nevertheless, given the range of bases studiedto date, particularly with CatBH and using fluoroaryl-borane activators,there is limited potential to significantly improve reactivity incatalytic electrophilic borylation by utilizing other monofunctionalbases.Changing L can impact differentsteps in opposite ways; e.g., whenL is a weak Lewis base it will bind weakly to CatBH and make hydrideabstraction less favored enthalpically, but it will enhance the electrophilicityof [CatB–L]1+/0 systems, bifunctional derivatives, e.g., 2-DMAP, alsohave beenexplored. While this was initially in stoichiometric C–H borylation,19 later work with compound 5  three coordinate and sufficiently electrophilic to interactwith arenes. The bifunctional nature of L is crucial as it introducesa basic site proximal to the electrophilic boron center (thus is apreorganized FLP). This facilitates C–H borylation via a six-memberedtransition state  species via TS2. This again emphasizes that the selection of L requiresa balancing act to prevent any one transition state becoming too highin energy. To date the systems in N values ≥ −1.5;however, benzothiophene (N = −2.6) did notundergo borylation. With fewer reports using bifunctional bases, itis possible that improved bifunctional base/hydroborane combinationsexist that will increase the scope further. The studies using 6 also highlight the complementary nature of catalytic electrophilicborylation, with groups often challenging in precious metal catalyzedborylation  tolerated. Furthermore,hindered sites can be borylated with 6 ,21 whereas iridium catalyzed borylation proceedsunder steric control.Moving beyond monofunctional bases in [CatB–L]mpound 5 420 and moracycle4, top.19ate TS1, 4 which i1+/0 species as the key electrophile effectingC–H functionalization. An alternative route to generate reactiveelectrophiles from CatBH is by binding a Lewis acid to an O or theB–H. As the Lewis acidity in dioxaborolanes is significantlyaffected by the π donor ability of the oxo groups,22 attaching a Lewis acid at O will modify theLewis acidity at boron. Our recent work utilized this approach incatalytic arene borylation with low coordinate zinc cations calculatedto prefer binding to O over the B–H unit (7-O vs 7-H).23 Using 10 mol % of compound 8 [CatB–L]mpound 8 5 as a prhe cycle 5, bottom10 (1510 activated 4-chloro-CatBH25 to form an electrophile that was highly effective in arene borylation.Compound 10 (5 mol %) was even sufficient to borylatebenzene  in high yield with ClCatBH. A highly electrophilic borenium cation is essentialwith B(C6F5)3, and a less Lewis acidicborenium cation not effective. 10 was proposed to interactwith the B–H of ClCatBH to generate electrophile 11 .26 Furthermore, stericallyhindered arenes, e.g., mesitylene, also underwent borylation using 10 in good yield; note, these hindered substrates are challengingfor iridium catalysts. This work combined with the zinc-catalyzedsystems indicates that electrophile binding to CatBH (and derivatives)to generate borocation equivalents is an underexplored area that maylead to further advances in catalytic borylation.In recent work, Wang and co-workers reportedthe use of the boreniumcation 10 6 as the phile 11 6. 11 theEAr. In contrast, the borylation of ethylbenzene with ClCatBH/10 gave ca. 1:1 mixtures of C4 and C3borylated products.15 This is potentiallydue to isomerization at the borylated arenium cation stage prior todeprotonation as observed in stoichiometric electrophilic borylation.27 Controlling the rate of deprotonation relativeto that of isomerization therefore offers a route to obtain distinctborylation products. Analogously, if deprotonation of the “kineticborylated-arenium cation” is reversible, then the thermodynamicborylated product could be accessed selectively. The latter was observedin our work on borylations using NHC-BH3/10 mol % I2.28 This forms NHC–BH2I that reacts with activated arenes by SEAr, withreaction of the HI byproduct with NHC–BH3 regeneratingNHC–BH2I. With N-Me-indole, theonly product observed was the C2 borylated product 12  Brønsted base. However,in the absence of a base 13 was formed reversibly, ultimatelyleading to formation of 12 as the only borylated product,consistent with 12 being calculated to be the thermodynamicproduct. Hatakeyama and co-workers also noted that, in borylationsusing BI3 in the absence of a base, reversible borylationoccurs, presumably enabled by the HI byproduct from SEAr.29Alongside increasing the scope, switching theregioselectivityin catalytic electrophilic borylation is also of interest. To date,the vast majority of reports generate the products expected from Soduct 12 7, withC3/hindered amine FLPsto borylate activated arenes. This enabled formation of trifluoroorganoboratesby electrophilic borylation. Notably, the addition of 5 mol % tetramethylthiourea(TMTU) catalyzed this borylation process, possibly by providing alower barrier deprotonation pathway or by enabling formation of differentreactive electrophiles, e.g., [(TMTU)BF2]+ cations.30These studies with NHC boranes also emphasizethat boranes otherthan dioxaborolanes can be useful in catalyzed electrophilic borylations.This is an underexplored area and one that may lead to distinct reactivity/products.This is exemplified by the use of BF31 in 2015 Fontaine and co-workersreported an FLP that catalyzedarene C–H borylation with PinBH.32 Vital to this process was linking a C–H functionalizationstep with a σ-bond metathesis step , which canbe viewed as a concerted SEAr type process.9 The concerted transition states accessible in systems containingpendant bases enables what are relatively weak (compared to boreniums)boron electrophiles to effect C–H functionalization. Presumably,this is due to the preorganized nature of unimolecular FLPs circumventingarenium intermediates and a separate deprotonation step with an exogenousbase . It should be notedthat an initial endergonic step to form the active FLP 14 is required, which can be termed a FLP preparation step. This stepis also present in derivatives of 14 and when using 6 and 9. It is associated with dimer dissociation/cleavageof a dative bond to access the FLP. This step has the effect of makingthe subsequent energy profile more endergonic, with the preparationenergy required generally greater the lower the steric bulk is inthe FLP. Therefore, developing systems where the active FLP is theresting state would be attractive for increasing the substrate scope.Building on breakthroughs inFLP chemistry,sis step 8. C–H fu20 and Fontaine34 revealed thattuning the boron substituents and/or reducing the steric bulk aroundN can reduce the barrier to C–H functionalization. A significantimpact on this step was observed by altering the substituents at boronto generate more Lewis acidic FLPs, with 15  and is a key obstacle that has preventedsignificant substrate expansion via this approach. This is also highlightedby the nucleophilic heteroarene thiophene proving challenging to borylatecatalytically using 14 and PinBH.12a In this case double C–H functionalization occurs,e.g., to form 17, but 17 does not undergoσ-bond metathesis with PinBH. To date successful σ-bondmetathesis, and thus turnover via approach (ii), has been limitedto FLP catalysts containing BH2 units . Finding alternative hydroboranes (to PinBH or CatBH) that undergoselective σ-bond metathesis with compounds such as 16 could significantly expand the substrate scope via this approach,as would identifying distinct BH2-containing FLPs thatare more Lewis acidic than 14  but still undergo metathesis with PinBH.Structure activity studies from the groups ofRepo with 15 9 able to14 based on aluminum, e.g., 18  does catalyze terminal alkyne C–H borylationwith PinBH.36 However, many main groupcompounds have been reported that catalyze alkyne C–H borylation,and this conversion is in general less challenging than arene C–Hborylation. Finally, in this section, it is noteworthy that a zinccatalyzed C–H functionalization/metathesis mechanism also wasexplored computationally starting from compound 8.24 This had an overall free energy span for theborylation of N-Me-indole of 26.6 kcal mol–1 (–1 for that via approach(i)  step. Thus, exploringother hydroboranes may facilitate this step and enable catalytic borylation via thisapproach.Analogues of al mol–1 10 bottomshown in 5. Note, 2Cat3); thus, PinBH is clearly preferable. In this area,Fontaine and co-workers have progressed from their initial sensitive(pre)catalysts to bench stable zwitterionic precursors of generalformula 20 could be synthesized on a >100 g scale and was effective in theborylationof a range of activated heteroarenes on scales up to 1 kg (for 21).For a process tobe widely used, it not only requires broad applicability,but it also needs to be operationally simple. This requires (pre)catalystsand reagents that are easy to handle . Thisactually excludes CatBH due to its sensitivity (to moisture) and itstendency to undergo substituent scrambling : (a) utilizing bifunctional bases; (b) accessing boronelectrophiles by binding the activator to an O or the B–H toform borenium equivalents; (c) minimizing the preparation energy requiredto access active FLPs; (d) controlling the relative rates of deprotonationversus isomerization to access alternative borylation regioisomers.For approach (ii) many of the considerations are the same as in (i),but this approach would also benefit from more diverse FLPs  being explored. This may help solve thecurrent challenge associated with the σ-bond metathesis stepthat currently limits the substrate scope in catalytic electrophilicborylation via approach (ii). Breakthroughs have also been reportedusing boron electrophiles outside of the usual dioxaborolane basedsystems. While this is an underexplored area that can enable novelchemistry, it does introduce an additional consideration—theprimary products from C–H borylation need to be syntheticallyuseful in their own right, or they must be able to be converted readilyinto useful organoboranes, e.g., pinacol boronate esters.Given the short timespan since the 2010 report using iPr)3  in the presence ofPMDETA  to effect C–Hborylation.40 The borylation proceeds viaa C–H metalation step to form an aryl–sodium complexthat then arylates B(OiPr)3, with the latterstep key to drive the C–H metalation to completion. This workis an extension beyond the classical stepwise ArylC–H metalation/B(OR)3 trapping—as NaTMP and B(OiPr)3 are mutually compatible, i.e., they do not react irreversibly witheach other. If a related system could be made to turnover, then itwould be complementary to catalytic electrophilic borylation methods.The complementarity is indicated by the stoichiometric NaTMP/B(OiPr)3 system being able to borylate the highly deactivated(in term of nucleophilicity) arene PhCF3. However, thereare still significant challenges to overcome to combine metalationwith a subsequent step 41 that would regenerate the strong base and closethe cycle.Movingforward, the fact that the catalytic approaches discussedabove all rely on electrophile based C–H functionalizationsteps is a limitation. It would be extremely interesting if fundamentallydifferent main group catalyzed arene borylation routes could be developed.For example, is a strong Brønsted base mediated catalytic borylationprocess feasible? Conceptually this would proceed via a strongly basicmain group compound metallating (deprotonating) an arene, and thiswould be followed by reaction of the Aryl-M product with an appropriateborane to form the arylborane, ideally with concomitant regenerationof the strong Brønsted base. A step toward this has been reportedrecently by Hevia and co-workers left, 12 who us42 This proceeds via a C–H/B–H σ-bondmetathesis type transition state , it does indicate thatwith the right system main group catalyzed electrophilic alkane borylationis possible, which would be a highly notable breakthrough.Finally, Vedejs’ seminal work on intramolecularborylationoffers a different mechanistic pathway to achieve C–H borylation.e inset, 12. This n right, 12.44 Whi